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- Front Matter: Volume 6279
- Plenary Papers
- Image Converter Streak and Framing Cameras
- Image Processing and Data Analysis
- Femto-Attosecond Light and Photoelectron Sources
- Pulsed X-ray Sources and Radiography
- Diagnosis of High-Temperature and High-Density Plasmas
- Ultrafast Lasers and Applications
- High-Speed Holography and Interferometer
- High-Speed Video Technique
- Trajectory, Impact, and Explosion
- Diagnosis of Ultrafast Phenomena
- Sensors for High-Speed Diagnosis (CCD, CMOS, Etc.)
- Shock Wave and Hypersonic Physics
- Photonics
- Detonics, Ballistics, and Dynamic Materials Response
- Opto-Mechanical High-Speed Cameras
- Poster Session: Image Converter Streak and Framing Cameras
- Poster Session: Image Processing and Data Analysis
- Poster Session: Femto-Attosecond Light and Photoelectron Sources
- Poster Session: Pulsed X-ray Sources and Radiography
- Poster Session: Diagnosis of High-Temperature and High-Density Plasmas
- Poster Session: Ultrafast Lasers and Applications
- Poster Session: High-Speed Holography and Interferometer
- Poster Session: High-Speed Video Technique
- Poster Session: Diagnosis of Ultrafast Phenomena
- Poster Session: Sensors for High-Speed Diagnosis (CCD, CMOS, Etc.)
- Poster Session: Shock Wave and Hypersonic Physics
- Poster Session: Photonics
- Poster Session: Opto-Mechanical High-Speed Cameras
- Additional Papers
Front Matter: Volume 6279
Front Matter: Volume 6279
Show abstract
This PDF file contains the front matter associated with SPIE Proceedings Volume 6279, including the Title Page, Copyright information, Table of Contents, Introduction, Congress Awards, Exhibitors, and the Conference Committee listing.
Plenary Papers
Photonics and laser optical diagnostics for investigations of high-speed transient processes
Show abstract
The present paper gives an overview on laser optical diagnostics used for studies of fast, transient phenomena. Examples
are cited, related to investigations of high power nonlinear laser radiation interacting with materials. These quasi explosively
developing effects require photonic techniques with highest temporal and spatial resolution, such as provided by
short-pulse and ultra-short pulsed lasers. As discussed, optical methods are useful for optimization of industrial production
processes and research topics. Advantages of coherent light in classical optical methods for beam deflection or phase
measurements are evaluated and compared with disadvantages, due to superimposed speckle patterns causing noise and
loss of information in higher parts of spatial frequency spectra. As a major breakthrough, features of holographic threedimensional
reconstruction of optical wave-fields are emphasized. Selected examples provide a comprehensive evaluation
of coherent optical diagnostic principles, as compared to non coherent techniques. Moreover, novel methods, using
carreer-frequency photography are stressed in which case speckles themselves are carrying information to be measured.
Further examples demonstrate the versatility and flexibility of ultra-short pulsed laser measurements down to the femtosecond-
range (1 fs=10-15s), whereby the Moire set-up chosen for demonstration can be substituted similarly by other
optical techniques. Summarizing, it can be stated that lasers provide unique tools for highest resolution, highest accuracy
measurements. Direct visualization, pump and probe techniques and other methods are adaptable to any industrial or
research related requirements. As shown in the outlook, meanwhile achievable XUV attosecond pulses (1 as=10-18s),
generated by fs-lasers, open the door for future (so far not yet fully predictable) applications, also in the field of ultra
high-speed diagnostics.
4DCapture/4DPlayer: evolving software packages for capturing, analyzing and displaying two- and three-dimensional motion data
James S. Walton,
Peter N. Hodgson,
Karen G. Hallamasek
Show abstract
In September 2002, during the 25th Congress on High Speed Photography and Photonics, 4DVideo described a general
purpose software application for the PC platform. This software (4DCaptureTM) is designed to capture, analyze and
display multiple video sequences. The application extracts trajectories and other kinematic information from (highspeed)
video streams.
Since 4DCaptureTM was originally described, it has matured, and a second application (4DPlayerTM) has been introduced
to support the distribution and viewing of video streams and kinematic data acquired by 4DCaptureTM. 4DPlayerTM is
"freeware". It may be redistributed to third parties, but it may not be modified.
4DCaptureTM provides a structured environment for experimental data. Cameras are treated as transducers-that is, a
source of technical data. The application provides an interface to the cameras for previewing the object-space,
calibrating the images, and testing. This application can automatically track multiple landmarks seen from two or more
views in two or three dimensions. Trajectories can be processed within the main application or they can be exported to a
spreadsheet where they can be processed or passed along to a more sophisticated, data analysis application.
4DCaptureTM also incorporates a simple animation capability and a friendly (FlowStackTM) user interface that assists the
end-user to capture and treat image sequences in a natural progression. 4DCaptureTM employs the AVI 2.0 standard and
DirectX technology.
4DPlayerTM can be used to view multiple video sequences simultaneously and perform simple measurements of
displacements and angles that vary over time. This application can detect and display the coordinates of landmarks
previously identified by 4DCaptureTM that have been embedded in the video streams.
Historical development and application of ultra fast diagnosis based on image tube in XIOPM
Show abstract
Xi'an Institute of Optics and Precision Mechanics of CAS was founded in 1962, but the research activities on high-speed
diagnosis in China can be dated back to 1958. The main goal of the Institute is developing some optical and
opto-electrical diagnostic tools of transient phenomena. This paper describes the historical development and application
of ultra fast diagnosis based on image tube in XIOPM.
High-energy x-ray imaging diagnostics of nanosecond pulse accelerators
Show abstract
X-ray imaging has been undertaken on Sandia National Laboratories' radiation effects x-ray simulators. These
simulators typically yield a single very short (<20ns) pulse of high-energy (MeV endpoint energy bremsstrahlung) x-ray
radiation with doses in the kilorad (krad (Si)) region. X-ray source targets vary in size from 2 to 25cm diameter,
dependent upon the particular simulator. Electronic imaging of the source x-ray emission under dynamic conditions
yields valuable information upon how the simulator is performing. The resultant images are of interest to the simulator
designer who may configure new x-ray source converter targets and diode designs. The images can provide quantitative
information about machine performance during radiation effects testing of components under active conditions. The
effects testing program is a valuable interface for validation of high performance computer codes and models for the
radiation effects community. A novel high-energy x-ray imaging spectrometer is described whereby the spectral energy
(0.5 to 1.8MeV) profile may be discerned from the digitally recorded and viewable images via a
pinhole/scintillator/CCD imaging system and knowledge of the filtration parameters. Unique images, analysis and an
evaluation of the capability of the spectrometer are presented.
Novel monochromatic x-ray generators and their applications to high-speed radiography
Show abstract
Novel monochromatic x-ray generators and their applications to high-speed radiography are described. The five
generators are as follows: a weakly ionized linear plasma x-ray generator, a monochromatic compact flash x-ray
generator, a super-fluorescent plasma generator, a cerium x-ray generator using a 3.0-mm-thick aluminum filter, and a
100micron-focus x-ray generator utilizing the filter. Using the linear plasma generator with a copper target, we observed
clean K lines and their harmonics, and soft flash radiography was performed with pulse widths of approximately 500
ns. The compact monochromatic flash x-ray generator produced clean molybdenum K lines easily, and high-speed
radiography was performed with pulse widths of approximately 100 ns. Using a steady-state cerium x-ray generator,
we performed real-time angiography utilizing an image intensifier and a high-sensitive camera (MLX) made by NAC
Image Technology Inc. with a capture time of 1 ms. Finally, real-time magnification radiography was performed by
twofold magnification imaging using a 100micron-focus x-ray generator and the high-sensitive camera.
Recent advance in streak and framing cameras in Shenzhen University
Show abstract
In this paper, we report on the recent development of streak and framing camera techniques in Shenzhen University,
such as soft X-ray streak image tube, synchroscan streak image tube, image intensifier and different kinds of newly
developed electronic circuits. In particular, we present three different kinds of streak and framing cameras, including a
soft X-ray streak camera with slit length of 30mm, dynamic spatial resolution of 15lp/mm and dynamic range of larger
than 900; a specially designed synchroscan picosecond streak camera with a repetition rate of 1MHz, which can provide
simultaneous time- and spectrum-resolved two-dimensional(2D) sampling information for biomedical imaging; and an 8
channel framing camera with exposure time of 3ns and dynamic spatial resolution of better than 20lp/mm.
Image Converter Streak and Framing Cameras
High-speed image converter instrument engineering of VNIIOFI is 40 years old
Vyatcheslav S. Ivanov,
Yuri M. Zolotarevsky,
Vladimir N. Krutikov,
et al.
Show abstract
A review of high-speed image converter instrument engineering in VNIIOFI during 40 years from
the moment of Institute foundation up to this time is presented.
Development of streak cameras for time-resolved experiments at the advanced laser light source laboratory
Show abstract
The Advanced Laser light Source (ALLS) infrastructure is a new state-of-the-art multi-beams femtosecond laser facility
currently in operation at INRS near Montreal, Canada. Multi-beams experiments and pump-probe geometry lead to the
need of synchronization instrumentation tools. The use of a wide range of energy radiation from hard x-ray up to infrared
light on the ultrafast time scale requires the development of ultrafast detector diagnostics tools to study the emission
spectrum of these sources. To fulfill these requirements, new streak cameras have been developed for ALLS facility. The
SV streak camera is a simple and compact multi-purpose instrument that will be used for beams synchronization with
picosecond time resolution and good spatial resolution. The FXR streak camera is dedicated to x-ray spectroscopy with
sub-picosecond time resolution combined with a very high spatial resolution.
Femscan: the development of the image dissector to a tube with femtosecond time resolution
Show abstract
The Image Dissector was one of the first all electronic TV tubes and was described by Farnsworth in 1934. (Ref 1).
Fifty years later, in 1983, more modern image dissectors were used to measure the electron bunch lengths in
synchrotrons. The advent of modern computers and high-speed electronics enables these rather elderly tubes to be used
in exciting new applications.
This paper described how we have adapted the image dissector to enable the development of low cost instruments with
exceptional bandwidth, sensitivity and sampling rate for optical signals.
Test of streak camera with high photoelectron beam density and energy
Sergey M. Gurov,
Petr A. Bak,
Yury D. Chernousov,
et al.
Show abstract
Streak camera with spiral scanning will allow measuring a single light signal with duration up to ten nanoseconds with
sub-picoseconds time resolution during all signal duration by means of using the whole 2D surface of screen. For
creation such a streak camera it is necessary to have a high density of photoelectron beam in order to have small beam
size and enough quantity of electrons in the resolution element. But the beam density increasing is limited by different
effects including temperature relaxation. Quite the contrary in typical streak cameras the beam density is reduced down
to single photoelectrons in the resolution element and then the number of electrons is integrated either on recurring signal
or along streak. Another way is the significant increase of electrons energy. This idea has been realized in the streak
camera with photoelectron energy up to 90kV and circular scanning by means of high quality RF cavity. The results of
testing of this streak camera are presented. The design of streak camera with spiral scanning is presented.
Research of range resolution of streak tube imaging system
Show abstract
Key factors that influence the range resolution of streak tube imaging system are discussed in this paper, and the
corresponding mathematical analyses are also made to predict the performance, finally, basing on the theoretical design,
we set up experiment to validate the range distinguishing ability of the system and get the practical resolution data. The
feasibility of streak tube imaging system is also demonstrated through the theoretical analysis and experimental results.
Test of Russian K004M and K008 image converter cameras when recording trigger lightning in Florida
Show abstract
There has been presented a brief description of test equipment and instrumentation for recording spatial-time parameters
of a lightning at the International Center for Lightning Research & Testing (ICLRT) in Camp Blanding that belongs to
the University of Florida as well as the first results of Russian image converter cameras test when recording a trigger
lightning.
Research of the streamer microwave discharge in a quasi-optical beam of electromagnetic wave with application of the K011 image converter camera
Show abstract
Nowadays of microwave (MW) gas discharge applications are actively investigated in different areas of science and
technology. Greatest optimism in applications is connected with streamer discharge forms.
A possibility of streamer form discharge applications is determined by their specific features. An efficiency of energy
absorption is close to 100% in this discharge. The discharge develops in a form of a spatial structure consisting of
streamer element interconnected. They explode at reaching of electrodynamic resonance. The discharge structure
represents a net of thin plasma channels. Gas temperature reaches several thousands of Kelvin degrees inside them. A
typical time of energy absorption by separate plasma channels is several units of microseconds. A velocity of a streamer
growth is about of - 106 cm/s.
Main physical mechanisms determining features of MW discharges have been qualitatively clarified nowadays. But
quantitative investigations of discharge creation processes are required for effective applications of these discharges. For
this purpose equipment, which has characteristics allowing detecting processes with resolution time in microsecond and
submicrosecond range, is necessary. In this work we represent investigation results of streamer MW discharge in air:
initial development stage, developed stage of a volumetric discharge and development of the discharge on a surface of
radiotransparent dielectric material. Investigations have been realized with a help of K011 image converter camera.
Optical trajectory diagnosis of 1.5MA wire-array Z pinches with fiber coupled streak camera
Z. Wang,
J. L. Yang,
L. B. Li,
et al.
Show abstract
A fiber coupled streak camera is developed and applied in Z-pinch experiments to investigate the optical trajectory of
wire-array implosions with one-dimensional (1D) spatial resolution of 100μ~400μ. The 1D image of the imploding
plasma is formed by a slit and relayed to a linearly arranged fiber array, which is capable of transmitting the 1D image
out from within the vacuum chamber. A mylar film is setup before the fiber array to absorb the X-ray light while
transmitting visible light into the fibers, which are coupled to a streak camera. And for X-ray diagnosis the mylar film is
substituted by an infra scinllator, which converts X-ray into visible light and relays it into the fiber array. The
experiments were performed on QiangGuang-1 facility. With the slit parallel to the axis of the wire array, optical
measurement of time-resolved radial distribution of the imploding plasma is carried out as well as diagnosis of X-ray
implosion dynamics. The 1D optical trajectory (radius versus implosion time) of imploding plasma is obtained. And
some discussions of the experiments are also presented in this letter.
Compact 8-way fast high voltage pulses generation with variable pulse width and interval time
J. Liu,
F. Zhang,
L. Li,
et al.
Show abstract
A programmable 8-way fast high voltage pulses generation built with avalanche transistors are studied. The fall time of
raw pulse is 200 ps with amplitude about 2 kV. The fall time is determined by transit time of carries in collector-base
region and it can be improved much by increasing the potential in this region. The pulse width can be switched
programably with 1-ns, 2-ns and 5-ns. The pulses interval time also can be switched programably. The cover time range
of 8-way pulses is more than 80-ns.
Application of image converter camera for investigation of discharges from an artificial cloud of charged water aerosol
Show abstract
Results of experimental investigations of optical characteristics of discharges from an artificial cloud of charged water
aerosol by using the K011miniature 9-frame image converter camera are presented in the paper. Application of high
speed image converter camera has allowed clearly distinguished the peculiarities of a final stage of three types of
discharges from the charged aerosol clouds. Each type of final stage is differed not only on optical and current
characteristics, but the sequence of formation. It was found that the type of final stage depends on character of
development the previous leader discharges in the gap "charged aerosol cloud-grounded rod on the plate". The most
frequently case is the formation of final stage after development of upward leader from the grounded rod and of
counterpart negative downward leader from the charged aerosol cloud boundaries. Simultaneously registered current
characteristics have shown significant correlation between optical and current characteristics of final stage of discharge.
More powerful discharge luminosity the higher current amplitude and the shorter final stage of discharge.
High frame rate imaging systems developed in Northwest Institute of Nuclear Technology
Show abstract
This paper presents high frame rate imaging systems developed in Northwest Institute of Nuclear Technology in recent
years. Three types of imaging systems are included. The first type of system utilizes EG&G RETICON Photodiode Array
(PDA) RA100A as the image sensor, which can work at up to 1000 frame per second (fps). Besides working
continuously, the PDA system is also designed to switch to capture flash light event working mode. A specific time
sequence is designed to satisfy this request. The camera image data can be transmitted to remote area by coaxial or optic
fiber cable and then be stored. The second type of imaging system utilizes PHOTOBIT Complementary Metal Oxygen
Semiconductor (CMOS) PB-MV13 as the image sensor, which has a high resolution of 1280 (H) ×1024 (V) pixels per
frame. The CMOS system can operate at up to 500fps in full frame and 4000fps partially. The prototype scheme of the
system is presented. The third type of imaging systems adopts charge coupled device (CCD) as the imagers. MINTRON
MTV-1881EX, DALSA CA-D1 and CA-D6 camera head are used in the systems development. The features comparison
of the RA100A, PB-MV13, and CA-D6 based systems are given in the end.
3D framing camera system based on sample cumulation method
Show abstract
A novel three-dimensional (3D) camera concept system could capture 3D image with thousands of pixels at range of
several kilometer in real time was presented. The camera used a pulse laser to illuminate the scene, a solid-stat chargecouple
device(CCD) sensor, and sample cumulation technology based on a gated binary image intensifier. The
cumulation charges captured in CCD carried the information of range. The system was designed to have some significant
advantages, such as low cost, simply schemes, high speed mainly limited to the speed of CCD frame capture. Potential
applications include navigation of autonomous helicopter, large target identification, sensing and guidance, auto collision
avoidance, robotic vision, atmospheric sensing and topography. In the paper, we discussed the fundamental principle and
schemes of the 3D camera system based on sample cumulation and presented the feasible experiment result with a photo
multiplier tube with binary character to simulate one pixel of the 3D camera system. Then we discussed the factors
which influence the quality of 3D image according to the experiment result.
Design and first tests of miniature K010X soft x-ray streak and single-frame camera
Show abstract
Description of a new K010X soft X-ray camera and the first results of it tests carried out in Russia and China are
presented. In a streak mode the full sweep time for a 2 cm sweep route length on the image converter screen is from
2 ns up to 600 microseconds. In a single-frame mode the corresponding frame duration is from ~10 ns up to ~ 660 microseconds. Spatial
resolution in a single frame mode was not less than 5 l.p./mm for soft X-ray radiation and not less 10 l.p./mm for UV
radiation. Spatial resolution in a streak mode for soft X-ray radiation was from 5 up to 10 l.p./mm and for UV radiation
on all the sweep ranges was not less than 10 l.p./mm, except for the range of 1 ns/cm where it was 5 l.p./mm. Limiting
temporal resolution for UV radiation was near 10 ps and a dynamic range was 200 when full sweep time was 60 ns.
The camera has small 430×115×200 mm dimensions, 5.0 kg weight and 10 VA power consumption.
Image Processing and Data Analysis
Computer modeling of shadowgraph optical setup
Mingyu Sun
Show abstract
For high speed flows with a short duration of test time, one has to construct an optical system without having an image
of it, which can be obtained only after running an experiment. In order to solve this problem, we propose a technique to
simulate the shadowgraph method together with the flow field by computer in this paper, so that one can optimize the
optical system on a computer before experiment. In the technique, the experiment is represented by the solution given by
computational fluid dynamics (CFD), and the image is obtained by tracing rays through the numerical solution as well as
the optical setup. The effects of optical components, such as the location of lens, the size of pinhole, the location of
image plane, are analyzed. Having this technique, even a beginner can construct an optimized shadowgraph system at a
negligible cost. The technique proposed can be used for analyzing schlieren system as well.
Computer analysis of the Schlieren optical setup
Masayuki Anyoji,
Mingyu Sun
Show abstract
In order to evaluate the influence of each component of the Schlieren optical setup, this work tries to simulate the whole
setup by a computer, so that one can get an immediate computer image after adjusting the component. The analysis is
based on the ray tracing method. All rays are traced from the light source to the recording plane, so that all components
in the light path can be investigated. In our analysis, Schlieren optical setup is decomposed to two main modules,
illuminating and recording optical setups. Each module contains typical optical arrangements that are commonly used.
The numerical models devised for the optical arrangements are proposed, and a few results indicating the effect of the
shape and the orientation of a cutoff are shown.
A robustness-enhancing method for real-time surface defection inspection
Show abstract
Surface defection inspection methods based on machine vision have lots of advantages over many other automatic
inspection methods, such as higher flexibility, lower overall cost, etc. However, the robustness of these methods is still
unsatisfactory. Inspection of magnetic rings which are rich in texture and have various defections is a typical machinevision-
based inspection task with high difficulty. Therefore, conclusions of the research on this problem are
representative.
In this paper, factors which lead to the variation of the inspection results are classified, and then a quantitative analysis
for inspection systems introducing a new concept of robustness index is proposed. As an approach for enhancing
robustness, the effect of the algorithm rule is focused on. The author extracts defection features on three levels in
designing the rule and come to a conclusion that a complete extraction on higher level can enhance the robustness of the
system after theory analysis and experiments.
Whole-field vibration analysis of a woofer's cone using a high-speed camera
Show abstract
In this paper we presented a method for whole-field three-dimensional (3D) shape measurement and vibration analysis of
a vibrating woofer's cone based on Fourier transform profilometry (FTP). A sequence of dynamic deformed fringe
images can be grabbed by high-speed CCD camera and saved on disk rapidly. By Fourier transform, filtering, inverse
Fourier transform and unwrapping these phase maps in 3D phase space, we can obtain the shape of the rapid vibrating
woofer's cone at different time. The results of our experiment indicate that the method, presented in this paper, can
efficiently deal with the surface shape measurement for rapid motion object and will be a promising one with the
development of high-speed frame grabber.
Rapid implementation of image processing onto FPGA using modular DSP C6201 VHDL model
Show abstract
Recent FPGA chips, with their large capacity memory and reconfigurability potential, have opened new frontiers for
rapid prototyping of embedded systems. With the advent of high density FPGAs it is now feasible to implement a
high-performance VLIW processor core in an FPGA. We describe research results of enabling the DSP TMS320 C6201
model for real-time image processing applications, by exploiting FPGA technology. The goals are, firstly, to keep the
flexibility of DSP in order to shorten the development cycle, and secondly, to use powerful available resources on FPGA
to a maximum in order to increase real-time performance. We present a modular DSP C6201 VHDL model which
contains only the bare minimum number of instruction sets, or modules, necessary for each target application. This
allows an optimal implementation on the FPGA. Some common algorithms of image processing were created and
validated on an FPGA VirtexII-2000 multimedia board using the proposed application development cycle. Our results
demonstrate that an algorithm can easily be, in an optimal manner, specified and then automatically converted to VHDL
language and implemented on an FPGA device with system level software.
Fluorescent image processing of image intensifier based on edge detector operator
Show abstract
The edge detector operator of image intensifier is a key problem for fluorescent image processing. This paper is intended
to serve for three purposes: (1). To present the general problem of Fluorescent image in a sufficient depth and extent, (2)
to present a complete algorithm for image processing including image sharpening and gradient operator. (3). to search
for a edge detector optimal for fluorescent image processing of image intensifier. It is expected that a edge detector
operator could provide a generic and robust solution to the reticle fluorescent noise images matching problem, which
could be an important breakthrough in computer vision, photogrammetry, and pattern recognition.
Mosaics of images from architectural and heritage structures
Ran Song,
John E. Szymanski
Show abstract
This paper presents an automatic robust system which relies only on the information contained within the original
images for the construction of massive composite mosaic images from close-range and high-resolution originals, such as
those obtained when imaging architectural and heritage structures. We first apply the Harris Corner Detector to extract a
selection of corners and, then, employ both the intensity correlation and the spatial correlation between the
corresponding corners for matching them. We estimate the lens distortion parameter and the eight-parameter planar
projective transformation matrix via the Levenberg-Marquardt algorithm. After the pairwise registration stage, we used a
global optimization strategy, solving a linear system of equations to produce a globally consistent alignment of the entire
set of original images. Lastly, image fusion using a weighted blending function together with intensity compensation
produces an effective seamless mosaic image. Comparisons with current commercial image-mosaic software are
favourable.
FFT-based 4-parameter global motion estimation
Show abstract
Motion estimation and compensation play important roles in video coding. The most commonly used motion estimation
technique is block matching. In recent years, the global motion compensation (GMC) is paid great attentions because it is
an important tool for a variety of video processing applications including for instance registration, segmentation and
video coding. The phase correlation is a typical global motion estimation (GME) method in frequency domain. In this
paper, a new 4-parameter GME method is proposed based on the Fourier transform properties of the tow images before
and after global motion. At first, the scale and rotation parameters of the affine transform are estimated according to the
formulas derived in this paper. Then the effect of scale and rotation of the affine transform are corrected with the
estimated parameters. After that, the well-known phase correlation technique is used to determine the two shift
parameters. An algorithm according to this principle is proposed in this paper, and simulation results show that the 4
affine parameters can be exactly estimated with our new method.
Noise reduction in electronic speckle pattern interferometry fringes by fourth-order partial differential equations
Show abstract
Noise reduction is one of the largest problems and biggest difficulties involved in electronic speckle pattern
interferometry (ESPI). Although the second-order PDEs denoising method is a useful tool of noise reduction for the
ESPI fringe patterns, its main drawback is that the second-order PDE model does not remove impulse noise, a 3×3
mean window filter is generally needed to improve the fringes. For overcome this main drawback, in this paper we apply
the fourth-order PDE denoising model to the computer-simulated and experimentally obtained ESPI fringe, respectively.
In both tests, the fourth-order PDE denoising model clearly outperforms the second-order PDE denoising model.
Experimental results have confirmed that the fourth-order PDE denoising model is capable of removing noise in ESPI
fringe images effectively.
A graduator test method based on dual dynamic image processing
Show abstract
The graduator is a very important standard device in the optical angular measuring instrument, which determines the
measure precision of the measuring instrument. A new graduator test method is discussed in this paper.
This test method is a dual dynamic imaging measurement method with dual digital microscope system, which acquires
the images of the graduator rotated by a rotating motor.
Here is the introduction of this method with more detail. At first, fix a graduator to be measured on a rotary stage, this
stage will be driven by a high precision programmable motor. Make the stage rotate with a constant angular velocity ω.
Then place the digital microscope system upon the graduator. The digital microscope system includes two digital
microscopes, which placed in the opposite diameter direction. Each digital microscope is made up of optical lens and a
CMOS electro-ocular. The sampling frequency f can be set in the control software of the elector-ocular. The two digital
microscopes make up a dual dynamic image acquire system. This system can acquire two images of the moving
graduator at the same time with the sampling frequency f. Then, a serial of the graduator images can be acquired after a
period of rotation, and there is a constant angular difference ω/f between every adjacent image. Each image of the
graduator includes several graduation lines, identify these lines and get the position of the lines with image processing
method. The measuring value of the rotate angle can be calculated from the adjacent line positions. Use the angular
difference ω/f as a standard value of the rotate angle. Compare the measuring value and the standard value with the
"comparing method of graduator measurement" formula. A compare result will be given to judge the graduator is good or
not at last.
The whole system is divided into four functional units: 1,the motion control unit;2,the dual dynamic imaging unit; 3, the
image processing unit; 4,the data analysis unit.
The measurement principle is introduced in the first part of the paper. In this part, the background of graduator
measurement and the theories of graduator measurement are referred. According to the measurement principle a system
design is made in the second part of the paper. In this part, the whole measure system is described: the structure of the
system, the function of each component and the specifications for the key components. An experiment system is build up
under the design, and some measurement data is obtained, the error analyses of the measure data is given at the last of
the paper.
Femto-Attosecond Light and Photoelectron Sources
A femtosecond electron diffraction system
Show abstract
The femtosecond electron diffraction (FED) is a unique method for the study of the changes of complex molecular
structures, and has been specifically applied in the investigations of transient-optics, opto-physics, crystallography,
and other fields. The FED system designed by the present group, consists of a 35nm Ag photocathode evaporated on
an ultraviolet glass, an anode with a 0.1mm aperture, two pairs of deflection plate for the deflection of electron beams
in X and Y directions, and the Y deflection plate can be used as a scanning plate while measuring the pulse width of
electron beams, the double MCPs detector for the enhancing and detecting of electron image. The magnetic lens was
used for the focusing of the electron beams, and the focal length is 125mm. The distance between the object(the
photocathode) and the image(the sample) is 503mm, and the size of electron beams is smaller than 17microns after
focusing, the convergence angle is of -0.075~0.075°, and the temporal resolution is better than 350fs.
A potential method to control thermal distribution in a solid state heat capacity laser
Yue Dong,
Jifeng Zu,
Liqun Hou,
et al.
Show abstract
Approximate formulas of transient temperature and stress distributions in the slab of a two-sided pumped heat capacity
laser (HCL) were attained by solving the heat diffusion equation. The thermal effects in the slab HCL were taken into
consideration. By finite element analysis, the transient temperature and stress distributions in the slab medium were
simulated with various boundary conditions, and the ANSYS simulations showed that when the pumping beam aperture
was less than the pumping area, the peak thermal stress of the slab would increase to 80MPa. Then a new method for
reducing thermal gradients between the outer surface of the slab and the internal portions in the slab was proposed, that
was the temperature of the outer surfaces of the slab to be adjusted during the lasing stage for a HCL. This method is
helpful to reduce the thermal peak stress to 40MPa. It not only provided a compensation for thermal gradients resulting
from the limitation of the beam aperture during the pumping stage, but also further improved the output power and the
beam quality. Our simulations are meaningful for designing a SSHCL especially the thermal management system in a
SSHCL.
Temporal-spatial MTF performance analysis of a proximity-focused-image intensifier as a camera electronic shutter
Shiming Xiang,
Hongquan Zhu,
Kuilu Wang
Show abstract
A specially designed-Proximity-focused-MCP-Image Intensifier (MCP-II) has been widely used for a high speed
diagnosis system as a ns-level-electronic shutter. Its temporal-spatial (dynamic) MTF or resolution are much concerned
in the engineering for single exposure conditions of various shutter times, and input illuminations as well. On basis of the
theory of Fourier spectrum and signal-to-noise, it has been analyzed in present paper that dynamic-MTF (or resolution)
of the MCP-II system is always deteriorated by its limited temporal frequency bandwidth, as well as S/N performance.
Several expressions are given to relate the device's dynamic MTF (or resolution) to its static MTF, input illumination
and S/N performances. The theoretical analysis is very useful in evaluating and designing some high speed diagnosis
systems with a proximity-focused-image intensifier as a electronic shutter.
Ultrafast microscopy of shock waves induced by femtosecond laser
Li Huang,
Yanqiang Yang,
Yinghui Wang,
et al.
Show abstract
Femtosecond-laser-induced shock waves in aluminum film deposited on alpha-quartz were generated at a repetition of up to
ten shocks per second. Using ultrafast time-resolved microscopy of shock waves in different thickness of aluminum
films, the shock velocity propagated in aluminum was measured to be 9.0±0.7 km/s. With shock wave equations of state,
shock pressures in aluminum and α-quartz were calculated to be 66(±15) GPa and 56(±15) GPa respectively, and final
temperatures in aluminum and alpha-quartz were calculated to be 281 °C and 104 °C respectively.
Pulsed X-ray Sources and Radiography
New developments in flash radiography
Arne Mattsson
Show abstract
The paper will review some of the latest developments in flash radiography. A series of multi anode tubes has been
developed. These are tubes with several x-ray sources within the same vacuum enclosure. The x-ray sources are closely
spaced, to come as close as possible to a single source. The x-ray sources are sequentially pulsed, at times that can be
independently chosen. Tubes for voltages in the range 150 - 500 kV, with up to eight x-ray sources, will be described.
Combining a multi anode tube with an intensified CCD camera, will make it possible to generate short "x-ray movies".
A new flash x-ray control system has been developed. The system is operated from a PC or Laptop. All parameters of a
multi channel flash x-ray system can be remotely set and monitored. The system will automatically store important
operation parameters.
High-speed hard x-ray phase-enhanced imaging
Show abstract
Conventional x-ray imaging relies on the differences in the absorption of the sample to provide image contrast. With the
small source sizes and large source-sample distances at synchrotrons, an additional mechanism, phase contrast, can come
into play. Phase effects, which include refraction and diffraction, can greatly enhance the image contrast. Phase contrast
is particularly useful in cases where the absorption contrast is weak. Added to this, the high x-ray flux available at
synchrotrons allows for unprecedented high-speed and high-resolution x-ray imaging. We demonstrate that high quality
time resolved images with sub-microsecond temporal and micrometer spatial resolutions are feasible. The range of
energy spectrum (5-150 keV) available at the Advanced Photon Source allows us to study a wide range of samples, from
soft tissues to high-Z materials. We will present preliminary results from the steel automobile fuel injectors and liquidair
sprays
Enhanced k-edge angiography utilizing a super-fluorescent x-ray generator with a gadolinium-target tube
Show abstract
The gadolinium plasma flash x-ray generator is useful for performing high-speed enhanced K-edge angiography using
cone beams because K-series characteristic x-rays from the gadolinium target are absorbed effectively by iodine-based
contrast media. In the flash x-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash
x-rays are produced by the discharging. The x-ray tube is a demountable cold-cathode diode, and the turbomolecular
pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage
pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the
condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current are
approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the K-series characteristic
x-ray intensities of gadolinium increased. Bremsstrahlung x-ray intensity rate decreased with increasing the charging
voltage, and clean K lines were produced with a charging voltage of 80 kV. The x-ray pulse widths were
approximately 100 ns, and the time-integrated x-ray intensity had a value of approximately 500 μGy at 1.0 m from the
x-ray source with a charging voltage of 80 kV. Angiography was performed using a filmless computed radiography
(CR) system and iodine-based contrast media. In the angiography of nonliving animals, we observed fine blood
vessels of approximately 100 μm with high contrasts.
Conceptual design of a high-frame-rate fast neutron radiography detector
Fa-qiang Zhang,
Zheng-hong Li,
Jian-lun Yang,
et al.
Show abstract
Fast neutron radiography offers means to inspect thick hydrogenous materials because of high penetration depth of fast
neutrons. Further more, quasi monoenergetic neutrons is relatively easy to obtain by neutron generators and it is helpful
for density inversion of targets, which has many difficulties in flash radiography. In order to investigate dynamic
processes, an intense repetitive pulsed neutron source will be used. Efficient detection of fast neutrons is one of the
hardest problems for fast neutron imaging detectors. In the system, a scintillating fiber array is employed to obtain a
detection efficiency of about 20% for DT neutrons. High-performance ICCDs and large aperture lens are taken into
account to increase the conversion efficiency and the collective efficiency. The properties of the detector are charaterized
in this paper.
Development of capillary Z-pinch discharge soft x-ray laser
Yuanli Cheng,
Qiushi Zhu,
Yonpeng Zhao,
et al.
Show abstract
The work on lasing in Ne-like Ar at 46.9nm by using a Blumlein transmission line is reported. The discharge system
consists of a Marx generator with maximum charging voltage of 300kV, a Blumlein transmission line and a pre-pulse
circuit. Both results of theory and experiment illustrate that the inherent high-amplitude pre-pulse (~5kA) causes serious
wall ablation, low homogeneity of plasma column and there would be no lasing. While the pre-pulse with an amplitude
of ~20A greatly reduces ablation, engenders uniform plasma column, and provides necessary condition for lasing. The
soft x-ray amplification in Ne-like Ar at 46.9nm has been achieved. The plasma columns are pumped by a 28~36kA
current pulse with 80ns half-cycle duration in a 3.1mm-diameter and 12cm-length capillary channels filled with Ar gas.
The full width at half-maximum of the laser spike is determined to be ~2ns and the output energy of the laser is
estimated to be 3μJ.
A sort of pulsed microfocal x-ray source
Kaige Wang,
Baoping Guo,
Jinchuan Guo,
et al.
Show abstract
A sort of pulsed microfocus x-ray source has been theoretically and experimentally studied. The portable x-ray source is
composed of three portions: LaB6 crystal cathode electron gun emitting system, electrostatic focusing system, and metal
target system. The electrons are emitted form the hot crystal cathode, and controlled by modulated Wehnelt grid bias
value and the ratio Dw/H, and concentrated by two-equal-radius-cylinder-electrodes focusing system. The x-ray photons
are irradiated by high energy electron beam bombarding metal target. The new x-ray source's general-purpose
capabilities such as pulsed radiation, focal spot size and luminance were preliminary tested. When the temperature of
LaB6 cathode is about 1900K and partial pressures being kept below 10-7 torr, the minimal focus diameter is merely
about 10 microns with the pulse width 65ms.
Design of remote control system for x-ray framing camera
Li Li,
Jinyuan Liu,
Fengxia Zhang,
et al.
Show abstract
This paper describes the implementation of a remote control system, where a PC and a single chip microprocessor are
used in a dedicated application to remote control an X-ray framing camera. It can implement some programmable
functions, such as driving pulse width adjustment, delay time adjustment between drivin8g pulses, MCP and phosphor
screen bias voltage control. These parameters can be selected with the key board in front panel or with the host
computer. A very simple communication link is presented using the ordinary communication protocol RS-232.
Diagnosis of High-Temperature and High-Density Plasmas
The application of high-speed photography in z-pinch high-temperature plasma diagnostics
Kui-lu Wang,
Meng-tong Qiu,
Dong-wei Hei
Show abstract
This invited paper is presented to discuss the application of high speed photography in z-pinch high temperature
plasma diagnostics in recent years in Northwest Institute of Nuclear Technology in concentrative mode. The
developments and applications of soft x-ray framing camera, soft x-ray curved crystal spectrometer, optical
framing camera, ultraviolet four-frame framing camera and ultraviolet-visible spectrometer are introduced.
Experimental modeling and high-speed photographic studies of gas laser cutting of sheet metal
P. V. Yudin,
A. P. Petrov,
O. B. Kovalev
Show abstract
The study is intended to the investigation of melt removal process during gas laser cutting of sheet metal. Model setup,
revealing visual access into the cutting kerf is developed. High speed photography technique is applied for the process
recording. Explanation of the melt removal process is given. Interpretation is based on the model cutting shooting
analysis and gas flow inside channel visualization data. Mechanisms of striated roughness generation are studied. Gas
flow separation is discovered to be the reason for elevated roughness of the cutting surfaces at the lower part. Flow
separation leads to vortex formation and reflux motion of the molten film, adjacent to the cutting front. Cutting regimes
that are free of these phenomena are also considered. Adequacy of the model experiment to the real case is demonstrated.
Accuracy of two-color pyrometry using color high-speed cameras for measurement of luminous flames
Show abstract
By the recent development in electronics, including new solid-state image sensors such as area CCD and C-MOS sensors
and the progress of image processing techniques, new imaging radiometers have been developed which
two-dimensionally acquire image data of objects moving at a high speed and under high temperature, and (graphically)
present the temperature distribution over the object immediately.
We successfully measured the temperature distribution and the term KL distribution, which is the absorption strength of
combustion in diesel engine cylinders or other luminous flames taking place at a high speed, using single-sensor color
high-speed cameras and applying two-color pyrometry introduced by H. C. Hottel and F. P. Btoughton.
The measurement accuracy depends on the accuracy of color reproducibility of the high-speed camera being used which
is considered a brightness pyrometer, because two-color pyrometry for measuring luminous flames is based on the
brightness temperature at two wavelength bands such as red and green.
In this paper, we present a method of maintaining the accuracy of measurement using a high-speed camera as a
brightness pyrometer and of two-color pyrometry that was developed based on it.
A Mach-Zehnder nonzero order joint transform correlator based on the YIQ color space for polychromatic pattern recognition
Show abstract
A novel nonzero-order joint transform correlator system with the Mach-Zehnder configuration for polychromatic pattern
recognition is presented. To remove zero order term is a very important thing for optical pattern recognition. We cleverly
utilize the Stokes relations to remove the large zero order term directly in only one step in this structure. In the proposed
technique, we investigate color pattern recognition with YIQ channels involving in-plane distortion such as rotations.
Furthermore, the utilization of minimum average correlation energy to generate the composite reference image for
enhancing the correlation output is also studied. The computer simulation results are presented to show the validity of the
proposed technique.
Ultrafast Lasers and Applications
High-power short-pulse fiber lasers
Show abstract
This paper describes characteristics of a short pulse doped rare earth fiber laser and amplifier. We have obtained
very stable pico-second and femto-second laser pulses from fiber laser. An all-fiber laser and amplifier of a
double-clad fiber are researched in detail. The pulse of 177fs at wavelength of ~1.50um has been got from fiber
laser. The energy of single pulse of 153μJ has been obtained after an amplifier of a double-clad fiber at
repetition-rate of 30 KHz.
Continuous-wave supercontinuum generation in a 100-m high nonlinear photonics crystal fiber
Show abstract
To our best knowledge, the most supercontinuum sources generated by use of cw pump lasers were obtained with fiber
interaction lengths of the order of 100 m to a few kilometers to enhance the optical nonlinearity. However, the material
loss was accumulated and the price cost was boosted in the long fibers. In this paper, CW supercontinuum generation by
use of a 1480-nm fiber-Raman laser (FRL) in a 100-m high-nonlinear photonic crystal fiber (PCF) together with a 76-km
single mode fiber (SMF) was demonstrated. The broadband supercontinuum was obtained with 10-dB bandwidth of 124
nm spanning from 1476 to 1600 nm. It was shown that the principal mechanism of the broadening could be assigned to
stimulated Raman scattering, four-wave mixing (FWM) and modulation instability (MI).
Double-end-pumped acoustic-optically Q-switched intracavity-frequency-doubling red laser
Show abstract
We report a high-power diode-double-end-pumped Q-switched Nd:YVO4 red laser through intracavity
frequency-doubling with a type-I critical phase-matched LBO crystal. At the repetition frequency of 26 kHz, the
maximum quasi-continuous-wave (QCW) output power at 671 nm was measured to be 9.2 W at the incident pump power
of 62.4 W with the corresponding optical conversion efficiency of 14.7%; the pulse width of about 106 ns; the pulse
energy of 353.8μJ; the peak power of 3.34 kW, respectively. The perfect performance indicated that the
double-end-pumped technique could effectively diminish the thermal lens effect, extend the range of the stable resonator
region and achieve a high optical conversion efficiency to obtain a high output power.
High-Speed Holography and Interferometer
Novel imaging interferometer for upper high-speed atmospheric wind field survey
Show abstract
A Novel Imaging Interferometer (NII) based on modified Michelson interferometer for surveying the physical properties
of upper high speed atmospheric wind filed is presented. Taking the natural airglow and auroral visible emission lines in
the upper atmosphere as surveyed source, NII can be used to retrieve the velocity and temperature of the upper high
speed atmospheric wind field through the interference imaging spectroscopy coupled with the Doppler effect of
electromagnetic wave. The optics system, survey principle, model and surveying method of four intensities are described.
Simulated experimental of velocity and temperature of wind field is shown. NII has the advantages of wide field of view,
bigger OPD, high resolution, achromatic, thermally stable, and is suitable for measuring upper atmospheric wind field.
Ultra-fast digital holography of the femto-second order
Show abstract
We report on pulsed digital micro holographic systems recording ultra-fast process of the femto-second order, by
spatially angular division multiplexing (SADM) and wavelength division multiplexing (WDM), respectively. Both
intensity and phase images of the digitally reconstructed images are obtained through Fourier transformation and digital
filtering, which show clearly the plasma forming and propagating dynamic process of laser induced ionization of
ambient air at the wavelength of 800 nm, with a time resolution of 50 fs and frame intervals of 300 to 550 fs.
A high-speed high-responsive PMT-based detector
Yuri V. Shcherbakov,
Gennadij D. Domashenko
Show abstract
A coupled pair of high-speed photomultiplier tube (PMT) based detector in series with the ultra-broadband amplifier has
been presented here. This combined device is intended for accurate measurements of high-speed low-luminous processes
in various fields of investigations. Their practical applications and parameters have been illustrated in many details.
Successful application of the device to studying the short gap streamer corona discharge in very fast transient stage of
primary streamer propagation has been illustrated. The device is able to be a very competitive product as compared to
new generation of the PMT-based detectors produced by the Hamamatsu Company who is the world leader in this field.
Optimization of the modified Sagnac imaging interferometer for full compensation
Show abstract
The modified super-wide-angle Sagnac interferometer (SASI) is designed for upper atmospheric wind measurement. The
formula of SASI's optical path difference (OPD) is derived, in which the OPD versus the sine series of incidence angle
in order of 4. The SASI's fully compensations of super-wide-angle, achromatic, thermal, wavelength-independent
thermal conditions have been investigated. The SASI configuration for the above compensations was successfully setup
by selecting correct glasses from the 113 kinds of glasses. The optimized SASI is made of ZBaF17 and QF14 glasses,
and the arm lengths are accurately configured. Based on the configuration of glass types and arm lengths of SASI, it
shows that SASI achromatic condition is satisfied synchronously for three aurora's emission lines, which are 557.7nm,
630.0nm and 732.0nm respectively. The relative error of SASI's lengths does not exceed 1%. The full field of view
(FOV) of the SASI is 6°. It is about 5° in full angle from SASI optical axis to CCD farthest corner. The first order fringe
occupies about 67% of the CCD area.
Photochromic diarylethene for holographic optical recording
Show abstract
A unsymmetrical photochromic diarylethene, 1-(2-methyl-5-phenylthien-3-yl)-2-[2-methyl-5-(3-fluorophenyl)thien- 3-
yl]perfluorocyclopentene (1a), was synthesized and its structure was determined by single-crystal X-ray diffraction
analysis. The compound showed good photochromism in solution, in PMMA amorphous film and in the singlecrystalline
phase upon photo-irradiation. Using the diarylethene 1b/PMMA film as recording medium and a nonpolarized
He-Ne laser (633 nm, 4 mW) for recording and readout, three types of polarization holographic optical
recording were carried out successfully. The results showed that different patterns can be displayed with differently
polarized readout lights, which can be applied in camouflage technology.
Optical fiber current sensor based on Bi4Ge3O12 crystal with enhanced Faraday rotation by critcal angle reflections
Show abstract
The feasibility of utilizing Bi4Gi3O12 (BGO) crystals as sensing element for optical fiber current sensors (OCSs) with
enhanced sensitivity is demonstrated. Based on the theoretical analyses of the magneto-optical properties of BGO crystal,
the Verdet constants of the crystal at different wavelengths are measured by employing the double frequency method. By
combining the measured absorption coefficients with the relations between the Verdet constants and wavelengths, the
magneto-optical figure of merit of BGO crystal is obtained. After that an OCS based on a BGO crystal with a magnetic
field concentrator and enhanced Faraday rotation by critical angle reflections is designed and experimentally
demonstrated. Finally, the influences of the phase shift caused by reflection, which is the main resource of the deviation
between the measured and the real values, are theoretically analyzed and numerically simulated. It is demonstrated that
an OCS based on BGO crystals with enhanced Faraday rotation could be developed into a practical OCS with a good
linearity and a large dynamic range.
Recording conditions of digital holography
Show abstract
Based on Fresnel diffraction formula, the spatial frequency distribution of the holograms recorded with plane and
spherical reference wave are analyzed. Using the sampling theorem and the condition of spectrum separation, the general
recording conditions of the digital hologram are deduced. The minimum recording distances and the offsets of the
reference wave for some practical recording configurations are given. The deduced recording conditions about off-axis
Fresnel hologram are different from others, which are different each other. The separating condition of the frequency
spectrum for Fourier transform holography is applied directly in their derivation. Moreover, they have applied different
other approximations in their derivation. No approximation is applied to our deduction. Therefore, the results derived
from our proposed method are accurate. The recording conditions of digital holography with general spherical reference
wave are presented firstly on our knowledge. The recording conditions of in-line and off-axis lensless Fourier can be
gotten directly as special case. The simulations and the experiments demonstrate that the method and the results are valid.
The results also show that only the sampling and separation conditions are met simultaneously, the reconstructed image
with high quality can be obtained.
High-Speed Video Technique
Lincoln Laboratory high-speed solid-state imager technology
Show abstract
Massachusetts Institute of Technology, Lincoln Laboratory (MIT LL) has been developing both continuous and burst
solid-state focal-plane-array technology for a variety of high-speed imaging applications. For continuous imaging, a
128 × 128-pixel charge coupled device (CCD) has been fabricated with multiple output ports for operating rates greater
than 10,000 frames per second with readout noise of less than 10 e- rms. An electronic shutter has been integrated into
the pixels of the back-illuminated (BI) CCD imagers that give snapshot exposure times of less than 10 ns.
For burst imaging, a 5 cm × 5 cm, 512 × 512-element, multi-frame CCD imager that collects four sequential image
frames at megahertz rates has been developed for the Los Alamos National Laboratory Dual Axis Radiographic
Hydrodynamic Test (DARHT) facility. To operate at fast frame rates with high sensitivity, the imager uses the same
electronic shutter technology as the continuously framing 128 × 128 CCD imager. The design concept and test results are
described for the burst-frame-rate imager.
Also discussed is an evolving solid-state imager technology that has interesting characteristics for creating large-format
x-ray detectors with ultra-short exposure times (100 to 300 ps). The detector will consist of CMOS readouts for high
speed sampling (tens of picoseconds transistor switching times) that are bump bonded to deep-depletion silicon
photodiodes. A 64 × 64-pixel CMOS test chip has been designed, fabricated and characterized to investigate the
feasibility of making large-format detectors with short, simultaneous exposure times.
Ultrahigh-speed, high-sensitivity color camera with 300,000-pixel single CCD
Show abstract
We have developed an ultrahigh-speed, high-sensitivity portable color camera with a new 300,000-pixel single CCD.
The 300,000-pixel CCD, which has four times the number of pixels of our initial model, was developed by seamlessly
joining two 150,000-pixel CCDs. A green-red-green-blue (GRGB) Bayer filter is used to realize a color camera with the
single-chip CCD. The camera is capable of ultrahigh-speed video recording at up to 1,000,000 frames/sec, and small
enough to be handheld. We also developed a technology for dividing the CCD output signal to enable parallel, highspeed
readout and recording in external memory; this makes possible long, continuous shots up to 1,000 frames/second.
As a result of an experiment, video footage was imaged at an athletics meet. Because of high-speed shooting, even
detailed movements of athletes' muscles were captured. This camera can capture clear slow-motion videos, so it enables
previously impossible live footage to be imaged for various TV broadcasting programs.
Design and implementation of high-speed CCD driving circuit based on CPLD
L. Zhang,
Y. X. Li,
X. J. Li,
et al.
Show abstract
In CCD detecting system of dynamic target, the design of high speed CCD driving circuit is a key technique in its
application. This paper, taking CCD IL-P3 produced by DALSA Company recently for example, according to the
demands of CCD driving timing, introduces a designing method of high speed CCD driving circuit. A CPLD device of
ALTERA Company's MAX7000S series is chosen as a hardware carrier to design the driving timing generator with
adjustable exposure time. After compiled and simulated in MAX+PLUSII, the program is fitted into the CPLD device by
using JTAG interface. And experimental results show that the expected CCD driving plus signals can be get.
The optimized method of video coding rate control based on rate distortion
Show abstract
A method of video coding rate control by joint picture-layer and macroblock-layer is proposed in this paper. In picturelayer,
the number of bits in each frame is pre-allocated on the whole, and a reference quantization parameter is
determined. Then, according to rate-distortion principle, when each frame is encoded, the optimized quantization
parameter is selected for intra-frame different macroblocks with the minimal distortion. The result of simulation shows
that the proposed method of video coding rate control can reduce or avoid buffer from overflow or underflow efficiently,
stabilify the output bit-steam and improve the peak signal-noise-ratio (PSNR) of re-constructed video signal.
High-speed deformation measurement using digital speckle correlation method
Hua Chen,
Dong Ye,
Rensheng Che
Show abstract
This article discusses an advanced deformation method based on digital speckle correlation method, which is
substantially more robust and has greater dynamic range than other full-field imaging technologies such as ESPI and
moiré. The system tracks the stochastic pattern applied to the measurement surface with sub-pixel accuracy. The object
under test is viewed by a pair of high resolution, digital CCD cameras. Two cameras having been mounted the locations
and attitudes were calibrated prior to measurement by combining nonlinear optimization with accurate calibration points.
The calibration points were formed by an infrared LED, which moved with 3-D coordinate measurement machine. By
using bilinear interpolation square-gray weighted centroid location algorithm, the imaging centers of the calibration
points can be accurate. The speckle images of the same measured zone from different directions for the specimen are
recorded by two cameras before and after deformation. Then the deformation displacement and strain of the specimen is
calculated by these images using digital speckle correlation method and geometrical relation of stereography. The
performance was demonstrated with real translation test.
Trajectory, Impact, and Explosion
Drift magnitude surveying in launching and taking-off processes of a large means of delivery
Show abstract
This paper deals with the approaching surveying principle and data processing for launching and taking-off of a large
means of delivery; moreover, the special requirements of the drift magnitude surveying optical system, the intermittent
performance of the synchronous high speed camera, the high speed tracing and accurate measurement of angles, and the
synchronous controlling, are also described. The approching survey means here the surveying range from the surveying
facility to the launching tower is about 100m~200m.
Observations of impact phenomena of spherical projectile on aggregated particles in random packing
Show abstract
The dynamic behavior of aggregated spherical particles subjected to the impact of a steel spherical projectile was
simultaneously recorded using two high-speed video cameras at different angles. The post-impact effects of a steel
projectile with an impact velocity of 1-20 m/s and an impact angle of 0-65° on the dynamic behavior of aggregated
particles were examined. The movement of the projectile after impact can be classified into four different types. In
addition, the effects of the particle's diameter of aggregated particles and the depth of the container on the four different
types of the projectile's movement were also examined. The use of small particles resulted in clear boundaries
demarcating between the penetration and the horizontal movement or the rebound of the projectile.
The application of the high-speed photography in the experiments of boiling liquid expanding vapor explosions
Show abstract
The liquefied-petroleum gas tank in some failure situations may release its contents, and then a series of hazards with
different degrees of severity may occur. The most dangerous accident is the boiling liquid expanding vapor explosion
(BLEVE). In this paper, a small-scale experiment was established to experimentally investigate the possible processes
that could lead to a BLEVE. As there is some danger in using LPG in the experiments, water was used as the test fluid.
The change of pressure and temperature was measured during the experiment. The ejection of the vapor and the sequent
two-phase flow were recorded by a high-speed video camera. It was observed that two pressure peaks result after the
pressure is released. The vapor was first ejected at a high speed; there was a sudden pressure drop which made the liquid
superheated. The superheated liquid then boiled violently causing the liquid contents to swell, and also, the vapor
pressure in the tank increased rapidly. The second pressure peak was possibly due to the swell of this two-phase flow
which was likely to violently impact the wall of the tank with high speed. The whole evolution of the two-phase flow
was recorded through photos captured by the high-speed video camera, and the "two step" BLEVE process was
confirmed.
Diagnosis of Ultrafast Phenomena
Photoelectron time-resolved spectra of silver halide micro-crystal adsorbing green-sensitizing dye J-aggregates
Show abstract
Microwave absorption and dielectric spectrum detection technology, with high time resolution (less than 1ns), was used
for non-contact measurement of electron property in solid materials. In this paper, the photoelectron decay time-resolved
spectrums of silver halide, which adsorbed the green-sensitive cyanine dyes J-aggregate, are measured by microwave
absorption and dielectric spectrum detection technology. From the experiment, we find that the photoelectron decay time
and the photoelectron lifetime of silver halide, which adsorbed the dye, is shorter than that of the pure silver halide; the
photoelectron decay time of silver bromide is faster than the photoelectron decay time of silver chloride, the free
photoelectron lifetime of silver chloride and silver bromide is 51.66ns and 13.84ns respectively; the variety extent of
silver bromide is bigger than that of the silver chloride after sensitized. The effect of the dye concentration on
photoelectron decay of silver halide is obvious, for silver bromide and silver chloride, the photoelectron decay become
faster while the concentration increases.
An experimental system using pulsed laser developed for detecting underwater objects
Show abstract
The influence of water backscattering on detecting ability should be considered emphatically when optical methods were
used to detect underwater object. The water backscattering light can be decreased by using a short pulsed laser in the
system and the precise distance of the detected object can be obtained easily. An experimental system made up of short
pulsed laser, received optical system, narrowband light filter, high speed detector, high speed data acquisition and
process system and so on was established. To validate its detection ability, this system was set into a large water pond to
detect several kinds of objects with different reflection index. We processed mass of experimental data get from above
experiment with simple method, and the processing result proved that this system had the ability of detecting objects
whose distance is about sixty meters. Because of its precise ranging ability, this system can be used with the combination
of a right scan device in three dimensional underwater imaging system.
Sensors for High-Speed Diagnosis (CCD, CMOS, Etc.)
Solid state replacement of rotating mirror cameras
Show abstract
Rotating mirror cameras have been the mainstay of mega-frame per second imaging for decades. There is still no
electronic camera that can match a film based rotary mirror camera for the combination of frame count, speed, resolution
and dynamic range. The rotary mirror cameras are predominantly used in the range of 0.1 to 100 micro-seconds per
frame, for 25 to more than a hundred frames. Electron tube gated cameras dominate the sub microsecond regime but are
frame count limited. Video cameras are pushing into the microsecond regime but are resolution limited by the high data
rates. An all solid state architecture, dubbed 'In-situ Storage Image Sensor' or 'ISIS', by Prof. Goji Etoh has made its
first appearance into the market and its evaluation is discussed.
Recent work at Lawrence Livermore National Laboratory has concentrated both on evaluation of the presently available
technologies and exploring the capabilities of the ISIS architecture. It is clear though there is presently no single chip
camera that can simultaneously match the rotary mirror cameras, the ISIS architecture has the potential to approach their
performance.
111-mega pixel high-speed, high-resolution CCD
Show abstract
A 111-Mega pixel, 92x92 mm2, full-frame CCD imager with 9x9 um2 pixel size has been developed for use in scientific
applications. Recent interest for ultra-high resolution imagers for electronic imaging OEM customers in various
scientific markets, including biotechnology, microscopy, crystallography, astronomy, spectroscopy, and digital
photography markets has lead to the development of the STA1600A 111-Mega pixel monochromatic charge-coupled
device. Innovative design techniques were utilized in the early development of this device, yielding low RMS noise and
high MTF for readout speeds ranging from 1 Mpixel/s to 10 Mpixel/sec. This paper will provide detailed information on
the design and performance capabilities of the STA1600A, as well as background information on the commercial uses of
this device.
A CMOS current-to-voltage linear conversion for low-input current, low noise and low power
Show abstract
This paper presents a very simple circuit of balanced two-stage current amplifier and regulated cascode (RGC) amplifier
to realize a linear current-to-voltage conversion. It can accept very low currents in the nA range. The noise model and
strategies for noise reduction are discussed. The circuit is designed for 0.18μm CMOS technology and verified by
simulations.
Shock Wave and Hypersonic Physics
Visual determination of the onset of irregular blast wave reflection
Show abstract
This paper presents further results of an ongoing experimental and numerical investigation into the unsteady process of
blast wave reflection from straight smooth surfaces. It is shown that basic blast wave phenomena such as the transition
from regular to irregular wave reflection can be adequately and conveniently studied in a laboratory environment by
using small charges with masses in the milligram range. While the laboratory scale generally provides greater
accessibility, it also imposes more stringent conditions on the diagnostics than the large-scale environment. The paper
reviews the previously found considerable discrepancies between numerical and experimental results for the location xtr
of the transition from regular to irregular wave reflection. These are caused by the initially minuscule size and gradual
growth of the Mach stem and the limited resolution of the recording material. Different techniques are used to improve
the accuracy of the experimental determination of the transition point, and a new combination of modern high-speed
photography with the traditional soot technique is shown to be the most promising tool for this purpose.
Dynamic pressure measurement of shock waves in explosives by means of a fiber Bragg grating sensor
Show abstract
A new technique for the dynamic measurement of detonation pressures by use of a Fibre Bragg Grating (FBG) sensor is
reported. A variation in pressure changes the wavelength of the FBG reflected light. In a detonation, the shock wave
passes the explosive with a velocity of ca. 7 km/s and the pressure builds up to ca. 20 GPa within 100 ns, so huge
differences in pressure exist in a small area. To prevent measuring the average pressure in a few mm, short FBG with a
length of about 0.5mm is developed by Hongkong PolyU and is inserted in the explosive. The light reflected by the FBG
is sent to a fibre optic Mach-Zehnder interferometer with a 3x3 beam combiner. Pressure induced wavelength shift will
cause a phase change of the interferometric signal. Using the 3 output signals of the interferometer, the phase can be
calculated. Interaction between the FBG and the ionization light generated by the shockwave is also demonstrated.
Research on method of measuring the time of remote explosion point
Show abstract
The time when the bomb explodes is one of the most important indexes to appraise the test. According to the principles
concerned with explosion radiation, the principle of measuring the time of remote explosion point and composition of
measuring system is introduced. Use CCD to record the explosion radiation, DSP to process and record the highcapacity,
high-speed video signals, and convert the exploding process examined by floating amplifier into digital signals.
Besides, the article analyzes the composing and structural design of the log's optical system, principle of electric control
and floating amplifier, dynamic range of the system, power analysis of the incident light, and how to improve the
accuracy of measurement in great detail.
Photonics
Photon emitting, absorption, and reconstruction of photons
Show abstract
Photon cannot keep itself unchanged from emission to absorption. The information encoded on the photon is also
changed due to interaction with environment. There has no definitely demonstration that the photon being absorbed is
the original one from ideal light source since the quantum mechanics itself is an indeterminate theory that the physical
measurement is only the probability. We divide the change of the photon state into two parts that one can be
compensated and the other cannot be compensated. A concept of photon reconstruction is introduced to explain every
optical phenomena including Raman scattering, multi-photon absorption, nonlinear phenomena, free electron lasing,
quantum entanglement, high order coherence, ghost imaging and the de-phase which result in error bits or information
loss in the quantum information process. An experimental result is explained to show that the signal photon can modify
the background even the energy of the photon is not enough for absorption in the wide-band gap semiconductor
material. The photon-current-voltage curve and dark-current-voltage curve of an absorption, grating, and multiplication
InGaAs/InP avalanche photodiode is analyzed to show that 1550nm input light modified the dark background even the
applied reverse bias voltage is far below the punch-through voltage. This increase of the dark count directly relates to
the input photons at the 1550nm wavelength but is not due to absorption in the absorption layer and insensitive to the
applied voltage.
Research on the new performance model for LLL TV imaging systems
Show abstract
Starting from threshold characteristics and night visual theory of the human eye the new quanta detector and linear filter
integrated performance model, universal threshold detecting theory and synthesis detecting equations for LLL (low light
level) TV imaging systems have been put foreword and established, which set up together active regularity and
connection between photon noise fluctuation theory and linear filter theory. By using the new performance model and
apparent distance detecting equations many specific properties of LLL TV imaging system, such as brightness
intensified, visual angle enlarged, signal to noise ratio and contrast transferred and attenuated, can be correctly
expressed, calculated and evaluated. The characteristics of the human eye can also be correctly reflected and described.
The dynamics of cavitation bubble clouds in high-intensity focused ultrasound field observed by high-speed photography
Xiaojing Li,
Hong Chen,
Mingxi Wan
Show abstract
High-speed photography is being considered as an effective technique to record the transient phenomena in medical
field. This presentation summarizes our previous work of using high-speed photography in the observation of cavitation
bubble clouds generated in high-intensity focused ultrasound (HIFU) field, aiming at the better understanding of the
cavitation mechanism during the medical application of HIFU. A high-speed photography system synchronized with
HIFU emission facilities was built up, and using this system we have investigated the dynamics of cavitation bubble
clouds (i) in the whole HIFU free field; (ii) in the focal region of HIFU free field; and (iii) near the tissue surface in
HIFU field. The spatial-temporal evolution of the bubble cloud and the characteristics of bubble cloud structures as well
as the possible explanations to the recorded phenomena are reviewed. All the results we got elucidated that the highspeed
camera is a potent tool to detect the cavitation phenomena in HIFU field.
Soliton self-trapping generation by femtosecond pulse in the highly birefringent photonic crystal fiber
Jing Wang,
Yan-mei Shi
Show abstract
Firstly, the possibility of yielding soliton self-trapping in the photonic crystal fiber (PCF) is analyzed, and it is found
that, due to the high modal birefringence of PCF, the femtosecond-order initial pulse must be considered in order to
realize the soliton self-trapping, so the effects of higher-order nonlinearity and higher-order dispersion need to be taken
into account. Secondly, based on the coupled nonlinear Schrodinger equations, the influences of higher-order nonlinear
and dispersive effects on the threshold value and the quality of soliton self-trapping are studied in detail with the
slip-step Fourier method. The numerical results show that, the higher-order nonlinearity doesn't affect the threshold
value but induces both the attenuation and red shift of the two polarized components, and the higher-order dispersion not
only influence the pulse shape and width of two polarized components, but also change the threshold value under
appropriate conditions. In conclusion, the PCF can also yield the soliton self-trapping with the interactions of all effects
above.
Application of diazonaphthoquinone/novolak photosensitive material for photography image formation
Show abstract
Historically diazoquinone/novolak- the two-component photosensitive material (photoresist) was efficiently used in
various industries. In the semiconductor industry it is used for the high contrast, high resolution binary image
formation for the integrated circuitry. Comparing with the silver halide photosensitive system which has Ag4
+ cluster or
T-grain sensitizing center that generates detailed gray scale (photographic density) black & white images, the
diazoquinone / novolak resist for the gray scale image formation has not been investigated thoroughly in the past.
Diazoquinone/novolak could be used in the photography field as one of the non-silver photosensitive materials and this
passive photosensitive material also has its broad exposure-energy response towards the image formation. Here in this
paper we provide this silver-halide supplement material to transfer our semiconductor photolithography binary process
experience of that resist to its photography application.
We also reported the TEM figures and the measurement data of the resist particle diameter after the photolithography
development process. The thick photoresist was coated on the aluminum substrate. Using critical dimension, CD =
2μm photomask to process several lots of wafers, the resist particles were collected and the particle size and its
distribution after the development process was obtained. Their size distribution mainly has dual separate distribution
peaks: 85% of particles have the diameter distributed around 23±3 nm and the rest 15% of bigger particles around
220±50 nm. Here in the experiment we use the standard-equivalent projection reticle to substitute the standard contact
mask to obtain 2μm CD latent images thereafter the corresponding particles throughout several lots. Because of the
unique role of DNQ, which is both the photo-sensitizer and the development inhibitor before its exposure, the correlation
of the resist particle size with respect to the developer concentration, the size of the radius of gyration, the
"photosensitizing center" and the "development center" is speculated. Generally the particle size distribution is mainly
correlated to the developer concentration, possibly also to the polymer resin molecular weight and the polymer / PAC
ratio etc.
We added our study of its photochemistry property (here specifically the UV-vis absorbance or optical density), provided
its spectroscopic response figures with respect to the sequentially increased exposure of the resist on quartz (250 - 550
nm and 300 - 450 nm). The relationship of the photographic contrast and its photochemistry property of the resist was
briefed.
Theoretical study of a quantum dot microcavity laser
Show abstract
Here we theoretically investigate a new laser device structure model based on a single semiconductor quantum dot (QD)
gain emitter, where the lasing occurs through discrete conduction states. A single QD is selectively placed in a high
quality microcavity, called a microdisk, which is resonant with an intersublevel QD transition. The quantitative results of
fully quantum-mechanical treatment here show that, when adjusting the QD-cavity coupling parameters to be appropriate
values, the microcavity coupling mode would lead to a very high photon intensity of the single QD microcavity laser.
The QD-cavity coupling interaction is modeled in the strong-coupling regime, and we conclude that the present QD
microcavity system itself can serve as a new novel terahertz laser with low threshold.
Spectral analysis of pulse-width jitter of optical pulse trains
Show abstract
We propose a technique for measuring the pulse width jitter of high repetition rate optical pulse trains. The technique is
based on spectral measurement of three different harmonics of the detected pulse train. The simulation results show that
the pulse width jitter would contribute a great amount of noise power to the total noise power when the product of pulse
width and angular frequency is larger than 1. We apply the proposed technique to characterize noise of a Fabry-Perot
Laser Diode. The pulse width jitter is estimated to be 2.3ps. Compared with the calculated 1.8% amplitude noise and
5.1ps timing jitter, the pulse width jitter is found not to be negligible.
New background estimation and suppression algorithm via Zernike-facet model
Show abstract
A new background estimation and suppression algorithm was presented. In the algorithm, targets and observing noises
were considered as mixed interferences of the image background. With this situation, image background was estimated
adaptively and then background suppression was done in order to improve the signal-to-noise ratio (SNR) of targets. In
this algorithm, firstly, a Zernike-facet model of image background was built up. Secondly, the total least squares (TLS)
method was used to solve parameters of the model. Finally, background estimation and suppression were done using the
model and its parameters. Simulations and several experiments demonstrating the effectiveness of this proposed
algorithm were reported. And results show that this algorithm can be effective to estimate background in mixed noise
environment and can preserve detail information of targets and improve SNR of targets. As a result, detecting probability
and false probability will be improved in next process for automatic target detection and tracking.
Detonics, Ballistics, and Dynamic Materials Response
Recording of essential ballistic data with a new generation of digital ballistic range camera
Show abstract
Scientists and Engineers still require to record essential parameters during the design and testing of new (or refined) munitions. This essential data, such as velocities, spin, pitch and yaw angles, sabot discards, impact angles, target penetrations, behind target effects and post impact delays, need to be recorded during dynamic, high velocity, and dangerous firings. Traditionally these parameters have been recorded on high-speed film cameras. With the demise of film as a recording media a new generation of electronic digital recording cameras has come to be accepted method of allowing these parameters to be recorded and analysed. Their obvious advantage over film is their instant access to records and their ability for almost instant analysis of records. This paper will detail results obtained using a new specially designed Ballistic Range Camera manufactured by Specialised Imaging Ltd.
Supersonic projectiles in the vicinity of solid obstacles
Show abstract
Solid obstacles close to (but not in) the flight path of supersonic projectiles influence the flow field and thus possibly the
projectile trajectory, even if no contact between projectile and obstacle occurs. In order to qualitatively clarify the basic
characteristics of such projectile/obstacle interactions, an initial investigation comprised of two different sets of
experiments has been conducted: live rounds were fired from a rifle so that they passed over a flat plate at distances
between 0.8 and 2.5 projectile diameters in the first set of tests, followed by a second set where a stationary projectile
model was placed in a supersonic wind tunnel to replicate the flow fields of the live range experiments. Time-resolved
monochrome schlieren visualization was used as the primary diagnostic tool in the first set of experiments, while singleshot
color schlieren images were obtained in the wind tunnel tests.
Analysis of base fuze functioning of HESH ammunitions through high-speed photographic technique
Show abstract
High-speed photography plays a major role in a Test Range where the direct access is possible through imaging in order
to understand a dynamic process thoroughly and both qualitative and quantitative data are obtained thereafter through
image processing and analysis. In one of the trials it was difficult to understand the performance of HESH ammunitions
on rolled homogeneous armour. There was no consistency in scab formation even though all other parameters like
propellant charge mass, charge temperature, impact velocity etc are maintained constant. To understand the event
thoroughly high-speed photography was deployed to have a frontal view of the total process. Clear information of shell
impact, embedding of HE propellant on armour and base fuze initiation are obtained. In case of scab forming rounds
these three processes are clearly observed in sequence. However in non-scab ones base fuze is initiated before the
completion of the embedding process resulting non-availability of threshold thrust on to the armour to cause scab. This
has been revealed in two rounds where there was a failure of scab formation. As a quantitative measure, fuze delay was
calculated for each round and there after premature functioning of base fuze was ascertained in case of non-scab rounds.
Such potency of high-speed photography has been depicted in details in this paper.
Opto-Mechanical High-Speed Cameras
Developments and achievements of optomechanical high-speed photography in China
Show abstract
The theories and technologies of the optomechanical high speed photography, which has basically met the requirements
in investigations of high speed, ultrahigh speed and other top scientific phenomena, have been developed and
improved these years in China. Compared with the high speed photography with converter tube, the optomechanical high
speed photography has a higher spacial resolution, larger image, and more frames since it only need one transfer from
optical image to chemical image or charge image.
Optomechanical high speed photographic techniques include high speed optics and mechanics, high speed
optoelectronics, high speed electrooptical shutter, and high speed opto-optical technique. In this paper, we will introduce
the technologies of high speed transporting film photography, ultrahigh speed rotating mirror photography, multiframe
high speed photography with solid imaging unit, microscopy high speed photography, raster principle and Cranz-Schardin principle in high speed photography, and extreme high speed photography based on optical principles.
Detecting system based on framing camera for suspension array
Show abstract
High speed imaging technology has been applied on biomedical research for a long history. Suspension array technology
is a new generation of biochip, which was widely used in fields of life science and analytical chemistry, and was
developed quickly. This study present a detecting system based on framing camera for suspension array. In suspension
array microspheres were used as the carrier of bio-probes and microchannels were used as analyzing platform. By
pre-dyeing of fluorophores in microbeads, the addressing of microbeads was implemented by optical coden. Bio-probes
attached to microbeads were distinguished by intensity of fluorescence. Suspension array was usually detected with flow
cytometry serially, which was slow relatively. Then a 2D parallel measurement system based on framing camera for
suspension array was established in order to increase the measurement speed. Liquid sample containing microsphere was
injected into microchannel by a 100ul syringe connected by a capillary. Microspheres flowing in the microchannel form
a 2D layer, which was illuminated freezingly by a pulsed Xenon lamp and imaged by a microscopy objective in parallel.
The microfluidic channel was designed and fabricated, which was a rectangle microchannel of 1mm×50um in
cross-section. The image was captured by CCD and transmitted into computer by frame grabber. Image was processed to
distinguish microspheres extract information from the background. Thus area measurement of suspension array in
microchannel was realized. Compared with flow cytometry, this technology increased analyzing rate greatly, which could
be thousands of microspheres per second.
Poster Session: Image Converter Streak and Framing Cameras
Test of Russian K004M image converter camera when recording natural lightning in Florida
Show abstract
The results of K004M camera tests when recording a trigger lightning are presented in paper [1] at this Congress. This
report is a continuation of paper [1] and gives the results of demonstration of the camera functioning when recording a
short spark in laboratory of the University of Florida (Gainesville, USA) and then a natural lightning in the University
and at the International Center for Lightning Research & Testing (ICLRT) in Camp Blanding that belongs to this
University. In so doing it has been shown that, except for luck, important conditions of successful record of a natural
lightning are exact synchronization of the moment of camera start with a required discharge stage as well as automatic
measurement of a distance to lightning and determination of its polarity.
Observation of vacuum arc cathode spot with high-speed framing camera
Show abstract
A copper vacuum arc cathode spot at current 10-100 A was imaged by three-frame camera K 0011 (BIFO Company,
Russia) with frame exposures 30 ns and 6 ns and spatial resolution up to 7 μm. It was found that spot splitting into
separate fragments occurs at currents higher than 50 A. The average fragment size was found to be 20 μm at current
about 10 A (cathode spot consists of a single fragment). With the rise of the arc current the average fragment size rises
too and reaches 50 μm at current 100 A (cathode spot consists of two or three fragments). The overall dimension of
region occupied by cathode spot fragments rises from 20 μm at current 12 A to 120 μm at current 100 A. Observations
with high temporal resolution (exposure time 6 ns) reveal the significant changes of cathode spot brightness occurring
within about 10 ns time interval.
Model for the brightness uniformity of fluorescence screen of image intensifier
Show abstract
The three elements of photoelectrical cathode, microchannel plate and fluorescence screen are important parts to imaging
quality of low light and ultraviolet Image intensifier. To do research and analysis work on the Fluorescence screen
parameter testing have practical significance to the understanding of the performance of fluorescence screen and then can
help to know where improvement should be made and then achieve a best performance entire tube, This article mainly
introduce the testing theory of the brightness uniformity of fluorescence screen of Image Intensifier and how to build a
mathematic model.
The streak camera system in HLS
J. G. Wang,
B. G. Sun,
Y. Cao,
et al.
Show abstract
HLS (Hefei Light Source) is an 800MeV electron storage ring in National Synchrotron Radiation Laboratory. To
measure electron bunch for Synchrotron Radiation and to understand the machine behavior during the operation, the
streak camera system has been built in HLS storage ring on April 2006. The streak camera system mainly consists of the
synchrotron light extracting optics setup and OPTOSCOPE the streak camera. The light extracting optics setup consists
of the light extracting path and the optics imaging system. The OPTOSCOPE the streak camera consists of a camera
main unit with input optics, a remote control unit, a CCD camera readout unit, a power supply unit, a Personal Computer
with a frame grabber interface card and ARP-Optoscope software package. The streak camera system operates with
synchroscan sweep mode or dual time base sweep mode. Controlling the streak camera and image acquisition is made by
the ARP-Optoscope software. At present, the system is used to measure the bunch length and the bunch interval in HLS
storage ring. Some typical results of the measurement are given.
Framing camera applied in the diagnostics of the pumping source performance
Show abstract
Taking advantage of the framing camera, the performances of the laser pumping source were studied. The framing
photographs of XeF2 photodissociation wave (PDW) under different experimental conditions had been taken, which
showed the forming process of the PDW. The variations of the radius, thickness and developing velocity of the PDW
with time had been obtained under different XeF2 initial concentrations. The temporal and spatial characteristics of the
PDW had been analyzed. The irradiative intensity of pumping source could be diagnosed by calculating the time
evolution of XeF2 photodissociation wave which was photographed by framing camera. The framing photographs of the
discharge plasma channel under different conditions had been obtained. The effect of the discharge plasma extension on
the efficiency resistance of the discharge circuit had been analyzed.
Theoretical analysis of a time focus and time amplifier cavity in streak tube
J. Liu,
L. Niu,
J. Li,
et al.
Show abstract
During the last few years, The time resolution of X-ray streak cameras have been improved to near 300-fs. Due to the
relative slower sweeping speed and initial energy distribution of electrons, It is hard to breakthrough the 100 fs time
resolution barrier. In this letter, time focus and time amplifier system is proposed. The time focus system is used to
compensate the time dispersion between photocathode and anode. The using of a time amplifier improves the technical
time resolution. The time focus and time amplifier system is designed to a compact fast electrons cavity structure.
Octagonal pyramid optical splitting system in nanosecond framing camera
Baozhong Shan,
Baoping Guo,
Shuyan Wang,
et al.
Show abstract
The high-speed photography is essential diagnostic tool in research on the ultra fast process. Usually, such process has
the duration of hundreds nanoseconds to dozens microseconds. The image diagnostic instrumentation is required to
obtain high speed framing images, which should be in fixed time in the duration with short exposure time and suitable
gap. A kind of nanosecond framing camera has been developed, which uses octagonal pyramid mirror to split one image
to eight. One image is split to eight in the space and each split image has equal optical energy. A nearly-pasted image
intensifier with gate selection is also developed to enhance the weak optical image. Each channel uses independent
image intensifier with gate and CCD camera. This system can capture eight images one time in the minimum interval
time of 10ns while the exposure time is 3ns The framing speed achieves 100 million/second. The dynamic spatial
resolution achieves 15 lp/mm. Many experiments, such as beam diagnose of electron pulse, plasma luminescence process
have adopted this camera and many useful results have been obtained.
A 3D framing camera with pulse laser and modulated receiver
Show abstract
It is convenient to apply three-dimensional (3D) detecting instruments to automatic drive, virtual reality modeling,
terrain reconnaissance, etc. It is presented that a new high-speed camera which achieves one three-dimensions image by
only one light pulse in this paper. It has a measurement range of one kilometer and a distance resolution of five meters.
This camera is composed with a pulse laser and three receivers which are made up with a Micro Channel Plate (MCP)
and a Charge Coupled Device (CCD) each. These parts are mature commercial productions that provide low cost and
high reliable to the 3D camera. As soon as the pulse laser emits a light pulse, the three receivers are modulated with
synchronistical control circuits. A 3D picture can be calculated by three different density images which are obtained by
that. The one-light-pulse-one-picture mode gives a flexible way to work with a gate signal. A 3D camera working with
high-speed gate signal can achieve high-speed photography easily. A mathematic model is established to describe
measurement range, distance detection precision and space resolving of the camera. The best modulation functions of the
receivers are given with consideration of white noise by Euler-Lagrange equation. Due to the best modulation function
we give a scheme is follows: The first receiver is modulated by a const gain, the second one is modulated by a linearly
increasing gain and the last one is modulated by a linear decreasing gain. This combination achieve both low noise and
simple structure. Because of the simple structure, several fibers which we named amending fibers can be used to amend
error of receiver modulation and synchronistical error. Analysis of the detection precisions of the camera and continuous
wave detection systems are carried out both in time domain and frequency domain. The results indicate pulse laser can
increase the detection range by suppressing background light greatly and decreasing imaging time. But it achieves lower
precision if the background light is faintness. Simulation experiment results are presented in this paper. A 1.4 kilometers
fiber was used in this experiment to simulate a 700 meters distant, a Laser Diode (LD) is employed to simulate the pulse
laser. A high voltage modulation circuit was designed to modulate the gain of MCP to implement the modulation
function. The experiment results with and without amending fibers indicated that the primary noises come from CCD and
the high voltage modulation circuit. The amending fibers can weaken the circuit errors in some degree. Future
improvement is described in the end of the paper also.
Poster Session: Image Processing and Data Analysis
Rapid regularization of LIDAR point cloud based on fractal interpolation with enhancement of edge features
Shengwang Zhang,
Youchuan Wan
Show abstract
The basic fractal theory and the fractal interpolation are studied, and the fractal property of remote sensing images is
refered in this paper. As to LIDAR points data, due to its difficulty of being handled by the traditional arithmetics, a
arithmetic of rapid regularization of LIDAR point cloud based on fractal interpolation with enhancement of edge features
is proposed on the analysis of the organizing forms of the point cloud. The arithmetic regularizes the points cloud into a
"rough image" by direct resample, and the edge pixels are differentiated from it, which are given new value by fractal
interpolation. And the non-edge ones retain their original value. The experiment proves that it can reduce the
computation, and enhance the main features effectively.
Edge detection and contour tracing of medical cell images
Luping Xu,
Jingrong Sun,
Lexuan Xi
Show abstract
It is important for medicine cell image to detect edge and trace contour In the process of recognition. The method of
equilibrium is used to improve the contrast between the target and the background for giving prominence to the target at
the beginning in this paper. Then edges in the image are detected with Canny operator, followed by edge figures
processing that utilizes fundamental transform processing in mathematical morphology. Finally, it makes use of eightdirection
chain code searching algorithm to trace contour, and carry on vectorization to the traced contour by using
improved variable-step-length algorithm in order to keep and recognize cells further. Better experimental results are
obtained by utilizing this method on edge detection and contour tracing of cell images.
Research on multi-pixels edge detecting and matching
Show abstract
Aiming at the influence of geometrical deformation on image matching, the method based on gray-level difference
between the nearby pixels detecting multi-pixels edge of image is put forward. To a 256 by 256 image, it needs only 0.14
second to detect edge which is 40% and 35% faster respectively than that of the Prewitt and Robert arithmetic. Applying
the method based on multi-pixels edge character to image matching, the influences of edge excursion can be improved
obviously: when excursion exists in single pixel point, the relative probability of image matching is improved to 67%;
when it exits in edge, it is improved to 50%. Research shows that this method is of simple model, high real-time quality
and anti-geometrical-deformation. Most importantly, it is simply conducted.
Effects of exposure time on the image in atmospheric turbulence
Chong Gao,
Jing Ma,
Li-Ying Tan
Show abstract
Image distortions during the propagation of optical beam in the turbulent atmosphere are provoked. Exposure time has
effect on the space distribution characteristics of light image in the focal-plane CCD or CMOS sensor. The effect of
exposure time on the spot size and shape is analyzed both theoretically and experimentally. The expression of spot size
variable with exposure time has been developed from the angle-of-arrival fluctuation by the longitudinal and transverse
components. In an optical free-space laser transmission experiment over a three-month period, measurements of spot size
at variable exposure times are shown. Theoretical and experimental results illuminate the important point that the effect
of exposure time must be considered for the optical design. The results show that the spot size decreases with exposure
time increasing. A rapid decrease is showed in the spot size for short exposure times up to about 20msec.
3D motion estimation for multi-object relative motion parameter and the centre of rotation using stereo sequence images
Show abstract
This paper proposes a general rigid motion model for estimating the multi-object 3D relative motion parameters and the
centers of rotation based on stereo sequences images. It is assumed that the correct establishing correspondence between
the matching points has been accomplished. For arbitrary two objects of these motion objects, firstly we set up three
space reference frames respectively on the two objects and the left camera, and their space relation is described
according to the coordinates of the correspondence points that lie on the two objects. Then, we design the two objects'
3D motion model through analyzing the rigid motion objects' character under the three reference frames. Thirdly, using
these points' 3D space coordinates acquired by high speed stereo photography, we can linearly figure out the
instantaneous relative 3D motion parameter and center of rotation through long sequence images after eliminating the
motion affection of the other motion object. For heightening the motion estimation method's robust, RANSAC algorithm
is applied to delete the outliers. Finally, simulation experiments are conducted using synthesized stereo sequence images
corrupted by noise and the experiment results prove the model's correction and the algorithm's validity.
Real-time 3D shape acquisition using a novel rotatable interlaced coded structured light
Show abstract
According to Sampling Theorem and image processing, structured light system has some limits, such as the
measurement resolution is restricted, some little gaps can not be measured and there are some errors or lost data on the
border of surface. A novel rotatable interlaced coding in real-time system of 3D information acquisition using structuredlight
imaging is proposed. It is consisting of two free directions of three-frame space-time light pattern, which can
acquire the denser 3D data from a single viewpoint. It can decrease the error from range image registration and advance
the system accuracy. The paper builds a real-time system of 3D profile measurement using structured-light. It allows a
hand-held object to rotate freely in the space-time coded light field, which is projected by the projector.
A noise removal algorithm for LIDAR intensity image based on orientation gradient and weighted threshold
Shengwang Zhang,
Youchan Wan
Show abstract
In this paper, an algorithm of LIDAR intensity image noise removal based on orientation gradient and weighted
threshold is proposed on the analysis of LIDAR imaging mechanism. It detects and removes the noise in LIDAR
intensity image based on the orientation gradient of the ground got from LIDAR distance information, during which
weighted threshold is adopted to calculate the threshold automatically. Experiments prove that this filter can detect and
remove the noise effectively and preserve the edge information of Intensity Image better.
The edge detection of hyperspectral image based on its proportion image
Yanjun Gong,
Dongmei Bi
Show abstract
Intensity-based edge detectors cannot distinguish whether an edge is caused by material changes. Therefore, our aim is to
classify the physical cause of an edge using hyperspectral obtained by a spectrograph. A method is presented to detect
edges in hyperspectral images. Analyzing proportion images of a hyperspectral image, we implement edge detection of
the hyperspectral image by using its proportion images. In edge part of hyperspectral image, the endmembers proportion
of mixed pixels is very small value. Edge detection can be implemented through these the distinctness of endmember
proportion in edge part. The method of edge detection is called edge detection based proportion image about
hyperspectral images.
A new image-reconstruction approach to optical computed tomography based on BP neural network
Show abstract
A new image reconstruction approach to optical computed tomography is proposed in which a BP neural network is used
to express the nonlinear relation between the change of optical properties inside the biology tissue and photons
distributing change around the surface. A modeling and simulation tool named Femlab and finite element method has
been tested wherein the forward model on a basis of the diffusion equation. Based on the forward problem, a BP neural
network was established to solve the inverse problem. Thus, the position and its corresponding optical properties of
tissue change could be recognized by the network. New approach was suitable for clinical application for its fast
reconstruct characteristic.
Averaging algorithm of reticle images in low-level-light weapon sight based on impact condition
Show abstract
The novel approach to the image noise problem of reticle images based on impact condition in low-level-light weapon
sight is proposed in this paper. The condition and process of the low-level-light weapon sight impact experiment were
analyzed, and then averaging algorithm of reticle images consists of two parts has been applied on the experiment. First
averaging and smoothing using a rotating mask methods were operated on Gaussian noise, to obtain a matching precision
with in 0.05 mil. Second the well known efficient median filtering smoothing method is performed to obtain the higher
matching precision. The potential of this averaging method is shown in the experimental results of reticle images in low-level-light weapon sight based on impact condition.
Real-time phase correction of optical images using adaptive optics system based on MEMS technology
Jie Li,
Haiqing Chen,
Peng Wu,
et al.
Show abstract
The possibility of compensating the wave-front distortion of an optical imaging system in real time has been a subject of
considerable interest. To compensate the wave-front aberration resulted by atmospheric turbulence, random gravity, heat
and component surface error during manufacturing, adaptive optics is an effective way. But conventional adaptive optics
has not found widespread acceptance outside the high-end astronomy community due to the cost and complexity. With
the development of micro-electro-mechanical systems (MEMS) based on silicon micromaching technology, it is possible
to develop a low-cost adaptive optics system. In this paper we will describe a micro-adaptive imaging system that has
proved the practical feasibility of real time optical phase correction. As a key component in our adaptive optics system, a
novel silicon bulk micromaching deformable mirror was used to compensate the wave-front aberration of optical image .
The laboratory experiments are also presented to reveal the benefit that such system can provide. Future possible
improvements are addressed as well.
A temporal algorithm for IR small targets detection
Show abstract
In order to detect small dim targets in IR image sequences, a temporal processing technique is investigated. Based on the
temporal difference models for background noise pixel, target pixel and clutter pixel, we formulate the detection problem
in 2 steps, Cross Correlation Target Detection method (CCTD) and Generalized Likelihood Ratio Test (GLRT). After
CCTD step, noise pixels in the image sequences are almost suppressed and only target pixels and a few clutter pixels can
pass the detection threshold. In order to further the targets detection in these pixels, an improved GLRT method is
developed. This improved GLRT method can suppress the clutter pixels sequentially and enhance the performance of the
temporal detection method. Theoretical analyses show that this algorithm can detect targets on very high detection
probability and very low false alarm probability. The effectiveness of the technique is demonstrated by applying it to real
world infrared image sequences containing cloud clutter and airplanes flying at long range.
Quantitative evaluation of laser jamming effect on imaging systems
Show abstract
The paper is devoted to a study of methods for quantitatively evaluating the jamming effect of a laser jamming device on
electro-optical imaging systems. Based on the theory of digital image processing and the Johnson criterion for target
detection and discrimination, four evaluation rules for laser jamming effect on electro-optical observation and aiming
devices are proposed. For the target-discrimination-grade, target-discrimination-probability, or target-discriminationrange
rule, the laser jamming effect is evaluated respectively according to the change of the target discrimination grade,
probability, or range of the imaging system after being jammed. For the correlativity rule, the jamming effect is
determined according to the correlativity between the two images of the imaging system before and after being jammed.
In order to evaluate laser jamming effect on electro-optical search and track systems, three evaluation rules are proposed
for the three working stages of the imaging system. At the searching or capturing stage, the jamming effect could be
evaluated respectively according to the change of the target detection or capture probability of the imaging system after
being jammed. At the tracking stage, whether the imaging system under jamming could produce effective tracking
errors, or whether the tracking errors exceed three times its normal tracking accuracy is proposed as the criterion for
determining whether the jamming is effective or not, and the jamming effect could be graded according to the jamming
success rate for numbers of tests. Finally, the test methods for laser jamming effect on electro-optical imaging systems
are discussed.
Small target fusion detection algorithm via image neighborhood entropy and univalue segment assimilating nucleus principle
Show abstract
Small and dim targets detection in the presence of strong background clutter is a challenging problem faced in many
applications including space surveillance and missile tracking. To solve this problem, a new fusion detection algorithm
applied image neighborhood entropy and univalue segment assimilating nucleus (USAN) principle is presented. In this
method the neighborhood entropy is used to locate small and dim targets. And the USAN principle is used to extract
some geometry features of targets including edges and inflexions. Based on these results, image fusion method is used to
detect real targets from noise and false targets. Finally, an iterative image threshold technique is proposed to label and
locate targets more precisely. Simulations and experiments show that the new fusion detection algorithm takes advantage
of the USAN principle and the neighborhood entropy method and it can detect small dim targets robustly, fast and
efficiently.
Correlation detection filter for imaging laser radar
Show abstract
Laser radar can simultaneously produce the intensity and range images, and the space resolution is high, so the
recognition performance is well, and it can choose the aim point of target. Laser radar is applied to many fields, such as
guidance, navigation, and becomes the research hot point in recent years. In the vertical detection of laser radar, the
algorithm is required not only solving in-plane rotation-invariant problem, also the distortion-invariant problem, and it
must satisfied the real-time. Correlation algorithm is a parallel processing procedure, detecting many targets at one time,
and its design can be implemented on the high speed digital signal processor. In the paper, a new filter named
CHF-MACH filter is presented, which combine multiple circular harmonic expansions into one filter through MACH
criteria. Because of the filter having the characters of the two filters, it can solve the problems of in-plane
rotation-invariance and distortion-invariance simultaneously, and meet the real-time requirement. The simulated range
image of laser radar is regarded as research target, and computing the PSR (peak to sidelobe ratio) values of correlation
output of the different objects, and plotting the PSR curves of the different angles. Simulating the scene of laser radar
which includes multiple objects, CHF-MACH filter performance is validated through testing with the different angles for
the objects, and the non-training images can obtain the well correlation output.
Optimizing image normalization algorithm for shape distortions
Junjie Liang,
Yucai Feng
Show abstract
In general, there are four basic forms of planar shape distortion caused by changes in viewer's location: rotation, scaling,
translation and skewing. For a good shape descriptor should be invariant to these distortions, a shape can be normalized
before feature extraction. Due to the drawbacks of the normalization algorithm, shape compacting proposed by J. G. Leu,
which normalizes rotation and skewing distortions incompletely, an optimized shape normalization algorithm is proposed
in this paper. The basic idea is first to get the compact shape which is invariant to translation and scaling distortions by
the shape compacting. Then, on determining the principal axis of the object shape, we get the angle included between the
x-axis and the principal axis, according to which the shape is rotated. Finally, the reversed object shape can be
normalized by the signs of the original image's central moments. Therefore, we can normalize a shape and its distorted
versions into a single one, with the following feature descriptor invariant to the above four distortions. The results of our
experiments demonstrate that the optimal shape normalization algorithm outperforms the existing shape compacting.
An automatic target recognition algorithm based on image matching with multiple sub templates
Li Zhi Qian,
Da Zheng Zhao,
Shen Xiang Tao,
et al.
Show abstract
The paper presents an upgrade target recognition algorithm based on the analysis of normal template matching algorithm.
The new algorithm firstly uses given template to generate sub templates at random or with certain principle, and then
matches each sub templates in search image to get possible areas of target, lastly finds the target from comparison among
the matching results. The paper at last gives the test results of the mentioned Algorithm. The results show: the new
algorithm greatly improves the efficiency, real-time ability, precision of the normal algorithm, and also it has an
advantage of easy realization, thus it is a good reference for solving the same problems.
Modified simultaneous algebraic reconstruction technique and its application to image reconstruction
Chunfang Li
Show abstract
Image reconstruction from projection is usually encountered in computerized tomography (CT) diagnosis. Based on the
factors of economy and practicality, optical CT is now developing in the direction of reconstruction from fewer views or
limited view range. However, in this condition, conventional simultaneous algebraic reconstruction technique (SART)
has shown some shortcomings. A modified simultaneous algebraic reconstruction technique (MSART) is presented here,
which takes into account not only the pixel value but also the segment length of the intersecting ray in error-correction
procedure. The computer simulation makes comparing studies of SART and MSART. The results show that MSART
solves the edge distortion effectively and makes encouraging improvement in reconstruction quality with sparse data.
Even applied to image reconstruction from projection with noise, MSART works well.
Spatial fusion algorithm of multispectral and high-resolution panchromatic images
Luping Xu,
Jing Yao
Show abstract
Image merging based on wavelet transformation requires a large computation complexity and may cause a severe lost of
the spectral information of the multispectral image. A new spatial image fusion algorithm based on fuzzy theory is
proposed in this paper. Through calculating the neighborhood homogeneous measurement (NHM) with the fuzzy
entropy, the structure information of the high-resolution panchromatic image was obtained. Two thresholds were defined
for different rules of fusion. Therefore, different fusion operations were taken accordingly. Experimental results
demonstrate that the proposed algorithm enhances spatial detail information of the merged image greatly and has a better
ability to preserve spectral information of the original multispectral image, compared with a wavelet image merging
algorithm.
Analysis on the cophasing errors of optical sparse-aperture imaging system
Show abstract
Optical sparse-aperture imaging system is one of the most potential techniques which can break through the physical
limits to the diameter of conventional filled aperture telescope. The image from individual telescope not only should be
overlapped, but also have the same phase at image plane. The purpose of this paper is to study the cophasing errors
which would degrade the performance of sparse-aperture imaging system. The analysis and discussion on system errors
which would lead to the cophasing error is presented, including piston error, tip/tilt error and pupil mapping error. The
results of the numerical simulation are presented on the system which has two sub-systems and certain parameters. The
effects of the piston error and tip/tilt error on the point spread function (PSF) of the system are discussed. The image
degradation due to the piston and tip/tilt errors are shown based on the imaging system which has three subsystems.
Study on real-time images compounded using spatial light modulator
Show abstract
Image compounded technology is often used on film and its facture. In common, image compounded use image
processing arithmetic, get useful object, details, background or some other things from the images firstly, then
compounding all these information into one image. When using this method, the film system needs a powerful processor,
for the process function is very complex, we get the compounded image for a few time delay. In this paper, we introduce
a new method of image real-time compounded, use this method, we can do image composite at the same time with movie
shot. The whole system is made up of two camera-lens, spatial light modulator array and image sensor. In system, the
spatial light modulator could be liquid crystal display (LCD), liquid crystal on silicon (LCoS), thin film transistor liquid
crystal display (TFTLCD), Deformable Micro-mirror Device (DMD), and so on. Firstly, one camera-lens images the
object on the spatial light modulator's panel, we call this camera-lens as first image lens. Secondly, we output an image
to the panel of spatial light modulator. Then, the image of the object and image that output by spatial light modulator will
be spatial compounded on the panel of spatial light modulator. Thirdly, the other camera-lens images the compounded
image to the image sensor, and we call this camera-lens as second image lens. After these three steps, we will gain the
compound images by image sensor. For the spatial light modulator could output the image continuously, then the image
will be compounding continuously too, and the compounding procedure is completed in real-time. When using this
method to compounding image, if we will put real object into invented background, we can output the invented
background scene on the spatial light modulator, and the real object will be imaged by first image lens. Then, we get the
compounded images by image sensor in real time. The same way, if we will put real background to an invented object,
we can output the invented object on the spatial light modulator and the real background will be imaged by first image
lens. Then, we can also get the compounded images by image sensor real time. Commonly, most spatial light modulator
only can do modulate light intensity, so we can only do compounding BW images if use only one panel which without
color filter. If we will get colorful compounded image, we need use the system like three spatial light modulator panel
projection. In the paper, the system's optical system framework we will give out. In all experiment, the spatial light
modulator used liquid crystal on silicon (LCoS). At the end of the paper, some original pictures and compounded pictures
will be given on it. Although the system has a few shortcomings, we can conclude that, using this system to
compounding images has no delay to do mathematic compounding process, it is a really real time images compounding
system.
An adaptive lifted pyramid for image compression
Jingbo Xiang,
Hongwu Su,
Xiuqin Su
Show abstract
In this paper, an improved Laplacian pyramid is proposed. We introduced additional adaptive lifted steps in the
Laplacian pyramid. Our pyramid is able to control efficiently the entropy of detail image. Hence, it provides improved
coding performance when compared to the standard Laplacian pyramid. Simulation results show that coding gains of up
to 1 dB for images when compared to the standard Laplaican pyramid, and the adaptive lifted Laplacian pyramid have
significantly lower entropy values.
Decorrelate hyperspectral images using spectral correlation
Liang Chen,
Daizhi Liu,
Shiqi Huang
Show abstract
This paper proposes a new algorithm for lossless compression of hyperspectral images. In our work we found
hyperspectral data have unique characteristic based on spectral context and adjacent pixel spectral vectors (curves)
highly correlate with each other. Pearson correlation coefficient is an effective measure of spectral similarity between
spectral curves to detect horizontal and vertical spectral edge. Thus, spectral correlation is used to prediction in spectral
direction for decorrelation of lossless compression of hyperspectral images. Experiments show the proposed algorithm is
effective, and it's more important that it has much lower complexity than other algorithms.
A sub-pixel correlation tracking method for extended target based on hierarchy model
Show abstract
A novel algorithm for detecting and tracking extended target against cluttered background using the improved MPC
distance and searching strategy with hierarchy model is presented in this paper. Comparing with the conventional
methods, the proposed method modified the correlation distance for MPC criterion for classifying target and background
as well, and designed an image shrinking methods controlled by the ratio of median filter and mean filter, which can
improve the computation efficiency. Moreover, we interpolate the image within a small window to obtain high accuracy
with the half pixels. Experimental results show, as compared to the conventional approaches, the proposed algorithm is
more robust, higher precision and has simplified computational complexity for tracking extended target against cluttered
background.
Study to real-time target recognizing system based on optical correlator
Show abstract
The recognition algorithm based on geometry texture character includes pattern matching, estimation function, and
determination tree. The advantage of above algorithms is easy to be programmed and realized by computer. However,
the recognizing operation consumes the mass of system source, which lead to the difficult to assure the good recognizing
accuracy under the high recognizing speed. Optical correlation processing system transmits information by photons and
operates by photo-electronic device, and realizes the target recognition by optical refraction, interference, and diffraction.
Compared with traditional computer image processing techniques, optical correlation system offer primarily two types of
benefits. On the one hand, optical correlation systems have an inherent capability for parallel processing, which can
transmit rapidly mass information. On the other hand, it changes the complex images processing problem into spot
recognizing in output plane. The correlation peak of high gray value appeared in the correlation plane can be used to the
proof to tell target from many kinds noises. The analysis in paper to how to make the complex matching filter, how to
determinate the truly correlation peak from others signal in correlation plane rely on neural nets technology could be
helpful to the study of optical correlation system used to the field of image recognition.
A real time image sequence processing algorithm for target ranging
Show abstract
It investigated in an image sequence procession algorithm for finding the distance from a moving target in space to the
mobile camera. Through 4-pairs points matching in adjacent image frame, the radial distance variation between adjacent
sampling times was calculated, with the target's azimuth, pitching, characteristic linearity and the space coordinate of the
camera jointed, a 4-order non-linearity equation was set up, distance from target to the camera at former time, i.e., the
only meaningful solution to the equation was solved, then obtained the distance from target to the camera at this time.
The ranging principle was explained, the ranging equation was deduced, the ranging error was analyzed, and the relative
measurement data and experiment results were given. It was suggested by our research that this algorithm could estimate
the distance from a moving target in space to the camera with only two image needed, an experiment was conducted to
illustrate the effectiveness and the validity of the algorithm. This scheme is valid to any rigid target in three-dimension
movement which could be superficially imaging and had a distance variation between adjacent sampling time meanwhile,
the algorithm can be realized with DSP and VLSI chips at 25 frame per second.
Color image encryption based on fractional Fourier transforms and pixel scrambling technique
Show abstract
Color image encryption based on fractional Fourier transform (FRT) and pixel scrambling technique is presented in this
paper. In general, color (RGB) image cannot be directly encrypted using a traditional setup for optical information
processing, because which is only adapted to process two-dimensional gray image. In the proposed method, a
three-dimensional RGB image is decomposed to three two-dimensional gray images (R, G and B values of the color
image), and the encryption operation will be done on each two-dimensional gray image, then the encoded color image is
available by composing the three two-dimensional encrypted images. The decryption process is an inverse of the
encryption. The optical encrypting systems based on the presented method is proposed and simulated. Some results of
computer simulation are presented to verify the flexibility and the reliability of this method. The quality of decrypted
images would be debased with the difference of the fractional order. The frustrated decryption of monochromic image
will affect the color of decrypted image. At the end of this paper, an all-optical and photoelectric encryption/decryption
systems solution are presented, and the principle of selecting optical devices are also given.
Morphology based adaptive preprocessing method of infrared image sequence
Show abstract
The paper presents an adaptive preprocessing method for infrared image sequence. Firstly an adaptive structuring
element (SE) construction algorithm is proposed. Secondly, based on morphological top-hat operation, the adaptive
background suppression of image sequence is taken. Finally, the image sequence adaptive segmentation is achieved by
using morphological opening operation. Some experimental results demonstrate that our proposed method is effective
and adaptive for infrared image sequence preprocessing.
Non-uniform MR image reconstruction based on non-uniform FFT
Show abstract
A Non-Uniform Fast Fourier Transform (NUFFT) based method for non-Cartesian k-space data reconstruction is
presented. For Cartesian K-space data, as we all know, image can be reconstructed using 2DFFT directly. But, as far as
know, this method has not been universally accepted nowadays because of its inevitable disadvantages. On the contrary,
non-Cartesian method is of the advantage over it, so we focused on the method usually. The most straightforward
approach for the reconstruction of non-Cartesian data is directly via a Fourier summation. However, the computational
complexity of the direct method is usually much greater than an approach that uses the efficient FFT. But the FFT
requires that data be sampled on a uniform Cartesian grid in K-space, and a NUFFT based method is of much
importance. Finally, experimental results which are compared with existing method are given.
An algorithm based on spatial filter for infrared small target detection and its application to an all directional IRST system
Jun-hui Luo,
Hong-bing Ji,
Jin Liu
Show abstract
For the small targets detection in single frame infrared image, a spatial filter algorithm based on an adaptive smooth filter
and the Robinson Guard spatial filter is proposed in the paper. The algorithm can detect the small targets in the undulant
background effectively with little target information loss; it is implemented easily by digital processor ADSP-TS201S
with high performance and successfully used in an all directional IRST system. The experiments show the effectiveness
of the detection performance.
The application of the multi-scale GVF model based on the B-spline lifting wavelet in medical images segmentation
Show abstract
Snakes, or active contours, are used extensively in computer vision and image processing application, particularly to
locate object boundaries. GVF (Gradient Vector Flow) model has resolved two key problems of the traditional
deformable model. However, it still requires both the initial contour being close to the target and a large amount of
computation. And it is difficult to process the cupped target edge. This paper analysis the characteristics of deformable
model firstly, then proposed a new method based on B-spline lifting wavelet. Experimentations based on GVF model and
MRI segmentation show that the proposed method is a good resolution to the initialization sensitivity and the large
computation.
A general image processing algorithm demo and evaluation system for infrared imaging
Show abstract
Research of image processing algorithm is one of the key issues for infrared imager development. Nowadays, researchers
of image processing algorithm and designers of infrared imager have presented many image processing algorithms. It is
necessary to evaluate the practicability, real-time performance and adaptability of all these algorithms in advance of
application. Based on virtual instrumental technology, a general demo and evaluation system for infrared image
processing algorithms is developed. The system configuration is described in detail. The extendable property of this
system made it suitable for various algorithms demo and evaluation. The vision impression of image processing
algorithms demo is processed through labview programming. Designers can evaluate the performance of image
processing algorithms in time. This system benefits designers to optimize their algorithms directly. Examples are applied
in this system to prove its functions. Trial results show it is a useful tool for infrared imager developer and image
processing algorithm designer.
An improved NAS-RIF algorithm for blind image restoration
Ning Liu,
Yanbin Jiang,
Shuntian Lou
Show abstract
Image restoration is widely applied in many areas, but when operating on images with different scales for the
representation of pixel intensity levels or low SNR, the traditional restoration algorithm lacks validity and induces noise
amplification, ringing artifacts and poor convergent ability. In this paper, an improved NAS-RIF algorithm is proposed to
overcome the shortcomings of the traditional algorithm. The improved algorithm proposes a new cost function which
adds a space-adaptive regularization term and a disunity gain of the adaptive filter. In determining the support region, a
pre-segmentation is used to form it close to the object in the image. Compared with the traditional algorithm, simulations
show that the improved algorithm behaves better convergence, noise resistance and provides a better estimate of original
image.
Enhancement of panoramic image resolution based on swift interpolation of Bezier surface
Show abstract
Panoramic annular lens project the view of the entire 360 degrees around the optical axis onto an annular plane based on
the way of flat cylinder perspective. Due to the infinite depth of field and the linear mapping relationship between an
object and an image, the panoramic imaging system plays important roles in the applications of robot vision, surveillance
and virtual reality. An annular image needs to be unwrapped to conventional rectangular image without distortion, in
which interpolation algorithm is necessary. Although cubic splines interpolation can enhance the resolution of
unwrapped image, it occupies too much time to be applied in practices. This paper adopts interpolation method based on
Bezier surface and proposes a swift interpolation algorithm for panoramic image, considering the characteristic of
panoramic image. The result indicates that the resolution of the image is well enhanced compared with the image by
cubic splines and bilinear interpolation. Meanwhile the time consumed is shortened up by 78% than the time consumed
cubic interpolation.
A weighted least squares image matching based target tracking algorithm
Show abstract
Moving target tracking is a basic task in the processing of high speed photography. Despite its widely applications,
Correlation tracking method can not adapt to the rotation and zoom of target and results in accumulation of tracking
error. The Least Squares Image Matching(LSIM) method which is used in photogrammetry is introduced to moving
target tracking, and a Weighted Least Squares Image Matching(WLSIM) based tracking algorithm is proposed. The
WLSIM based algorithm sets weights according to the target's shape for the Least-Squares Image Matching Algorithm,
as a result matching error produced by the background in the tracking window can be avoided. Experimental results are
shown to demonstrate the robustness, efficiency and accuracy of the proposed algorithm.
Comparison of anamalous range image suppression methods of laser radar and combination of filter methods
Show abstract
Laser radar could obtain the intensity image and range image synchronously, and the target is easily distinguished because of different range values, so the "Ladar" has abroad applications. However, in the range image proceeding, the target is always disturbed to illegible by speckle and random noise, how to retrain the noise as well as keep the image information becomes the crucial problem. This paper is based on the three filter methods: histogram, median, multiple level median, the methods are all based on the theory that the probability of range anomaly is far less than that of no anomaly, using the theory of stat sequence filter, could restrain the speckle and random noise very efficiency. The three methods have the different effect on the noise restraining and keeping edge from each other. To choose the methods, the contrast of each other method is made and the contrast and the characteristic have been got, the simulated result is obtained. This paper draws the conclusion that the histogram method has the best synthetically effect of the three methods, especially in the keeping edge. In the last, the filter methods are combined together to filter the raw image in different order and is found that the different order will make the effect different on the image; the reason is that the different order makes the initialization diverse for the filter methods. The result was showed in the end of the paper, while discussing the reason of the effect of the order.
Object-oriented information extraction technology from QuickBird pan-sharpened images
Show abstract
The high spatial resolution Remote Sensing image has richer information than the low or middle resolution image, such
as structure and texture information. Traditional image classification technology which only uses spectral information of
pixels is not suitable for the high resolution image. In order to make full use of the rich information, object-oriented
thought is introduced into the high resolution information extraction. In contrast to traditional methods, the basic
processing units of object oriented image analysis are image objects, and not single pixels. It could fully integrate
spectral values and spatial information such as: shape, size and contextual relationship. The objective of this study is to
extract kinds of information from QuickBird image of the urban area using the object-oriented information extraction
approaches. Image processing includes geometric correction, HIS fusion, image segmentation and classification using
the integration of fuzzy classification and the nearest neighbor (NN). 84.82% overall accuracy is achieved with this
approach, while only 73.87% is achieved with traditional pixel-based method. It shows that object-oriented approach is
promising in providing detailed and accurate information about the physical structure of urban areas from the high
spatial image.
Superresolution reconstruction of images by weighted wavelet bicubic interpolation search algorithm
Show abstract
The variable relationship between the threshold of high-frequency extrapolation and the entropy of its correspondent
reconstructed image in the Wavelet Bicubic Interpolation Algorithm is analyzed. The information entropy is used as a
cost function and a Maximal Entropy Wavelet Bicubic Interpolation Search Algorithm is proposed. This algorithm can
automatically search an extrapolation threshold to reconstruct an image with maximal entropy. Although the detail
information of the reconstructed maximal entropy image is larger than its original image, it may introduce a lot of
uncertain and incorrect information. In order to remedy this shortcoming of the proposed algorithm, a new cost function
based on the old one is established. The new cost function can not only remedy the shortcoming of the entropy function
as a cost function, but also a weight introduced in the new cost function can be adjusted to reconstruct different
superresolution images to satisfy different practical requirements. Thus a Weighted Wavelet Bicubic Interpolation
Search Algorithm is established. The experiment results prove that if the distribution of the processed images is close to
the maximum likelihood distribution, a large weight will be selected to reconstruct a relative better superresolution
image with better details, and if the distribution of the processed images is far from the maximum likelihood distribution,
a little weight will be selected to reconstruct a relative better superresolution image with better visual effect. Therefore,
the weight in the new algorithm can be selected from the requirements to satisfy different practical cases.
New 2D adaptive image thresholding method based on within and between cluster scatter
Yunyan Zhou,
Kuntao Yang
Show abstract
In this paper, a novel image thresholding approach based on within and between cluster scatter of the 2D histogram is
proposed. 2D Otsu's method not only utilizes the gray-level information of each pixel but also synthesizes its spatial
correlation information within the neighborhood, so it is more valid in the threshoding. However, it doesn't take into account
of the within cluster scatter, sometimes it can't reach the optimal thresholding validity. In this approach, within and between
cluster scatter are integrated to improve the algorithm. The threshold vector that maximizes between cluster scatter and
minimizes within cluster scatter at the same time is regarded as optimal threshold. In order to avoid exhaustively computing
within cluster scatter, we simplify the threshold recognizing function via replacing within cluster scatter by the difference in
total covariance and between cluster scatter. As the total covariance of a given image is a certain constant, the simple
algorithm will decrease complexity of computation greatly without affecting the segmented result. Experimental results show
that our proposed approach not only performs well and effectively but also is more robust when applied to noisy image.
Image blurring of narrow laser beam transfer in ocean and through wavy sea surface
Show abstract
In the detection of underwater object by air-born lidar, a narrow laser beam reflected by the sea bottom or the underwater
target transfers in the ocean and refracted through the wavy sea surface, then received by the receiver carried by plane
over the sea surface. Because of the scattering by the suspended particles and the effect of the wavy sea surface, the
received signal will to some extent blurred, which will greatly decrease the image quality of the lidar system. Computer
simulation by Monte Carlo method was employed to describe the process of narrow laser beam transferring in the ocean
and refracted by the wavy sea surface. As the result, the intensity distribution on the receiver can be got as well as the
property of image blurring after transferred thought the ocean water and refracted through the wavy sea surface. The
relations between this property and the optical property of seawater, the wind speed above the sea surface were analyzed.
Double-channel on-line automatic fruit grading system based on computer vision
Junxiong Zhang,
Yi Xun,
Wei Li,
et al.
Show abstract
The technology of fruit grading based on computer vision was studied and a double-channel on-line automatic grading
system was built. The process of grading included fruit image acquiring, image processing and fruit tracking and
separating. In the first section, a new approach of image grabbing by employing an asynchronous reset camera was
presented. Three images of the different surfaces of each fruit would be collected by rolling the fruits when they passed
through the image-capturing area. To acquire clear images, high-frequency fluorescent lamps supplied by three-phase
alternating current were used to illuminate. In the image processing section, the diameter and a color model were used to
identify the grade of the fruits. Fruits were graded into four grades by size, and two by color. Each fruit identified was
tracked and separated by a novel algorithm which was realized with a PLC (Program Logic Controller). The whole
grading system was tested with 1000 citrus. It could work stably when the grading capability was twelve citrus per
second and the grading level was nine. The on-line grading results indicated that the accuracy of tracking and separating
was higher than 99%, and the ultimate grading error was less than 3%.
Multiple facula targets recognition based on edge and region search
Show abstract
An algorithm of multiple facula targets recognition based on edge and region search in full field of a frame of image is
presented. Firstly, the image is segmented by binarization and the burr around the targets is removed by morphology
processing. Then every facula target's edge and region is found and numbered in turn. Experimental results on simulated
images and real images are shown to validate the presented algorithm.
Automatic interpretation and precision detecting of target's axis in image sequences
Xiaoli Hu,
Yihui Xue,
Sanxi Zhang,
et al.
Show abstract
Based on high speed photography video image sequences, target's motion parameters can be obtained by interpreting
image sequences and calculating with interpretation results. The principle of traditional interpretation methods all
obtained spatial coordinates of target's point based on target plane coordinates of target's point. If obtaining 3D attitude
of rigid(spatial orientation of target's axis)with the information of two points' spatial coordinates, then the precision is
difficult to reach the expected value. But if we interpret by extracting target's axis, then the interpretation precision and
measuring precision can be advanced. In this paper interpretation technique of target's axis automatic detecting and
tracking based on target's model and "WYSWYG" is proposed, detecting method of axis interpretation precision is
introduced and the precision is analyzed.
Analysis of scannerless imaging lidar in large field of view condition
Show abstract
Scannerless lidar has advantages of high frame-rate, large field of view (FOV) and miniaturization etc, it is especially
valuable for military and aerospace engineering applications such as 3D vision, target recognition, autonomous
machinery guidance and collision avoidance etc. In this paper, we analyzed the performance of scannerless imaging
lidar, to investigate this, the overall system is divided into 6 modules according to various functions including
transmitter, optical antenna, atmospheric transmission, target property, detector, data processor etc., whereas the physical
processes of every module have been studied and corresponding mathematical models are also set up. The fundamental
problem of imaging lidar system is numerical solution of lidar equation, however common lidar equation regards target
as a point reflector with the assumption that back reflecting light is distributed uniformly in all directions in 2Π solid
angle, which is not for large FOV situation. In large FOV condition, the target can be regarded as a Lambertian reflector;
the intensity of light back reflected from different part of the target is not same but follows the Lambert cosine law, so
we make a modification for lidar equation, and finally all data from every module are coupled into lidar equation,
through modified lidar equation calculation, the relationship between maximum acquisition range and emission power is
discussed.
Poster Session: Femto-Attosecond Light and Photoelectron Sources
Analysis of the output impulse of PCSS triggered by femto-second laser pulse
Show abstract
In this article different experiments are carried out to exam some key elements that influence the performance of PCSS
(Photoconductive semiconductor switches). The experiments include the bias voltage over the switch, the trigger pulse
energy and position. From the results we got the relationship among the elements and the output impulses. The bias
voltage controls the output linearly; the rise of trigger energy increase the export voltage but when the energy get over
280μJ this trend slow down and the export voltage go to a fixed value; different positions change the export voltage and
the peak value appears at the area near the cathode. The results were analyzed and explanations were given. From the
discussion we give the evidences in helping to explain the linear mode, and point out an efficient way to use the laser
energy for PCSS. Some tests methods are introduced and will be done in the future.
Self-starting 21-ps Ti:sapphire laser with high beam quality
Show abstract
A self-starting all-solid-state picosecond (ps) laser was demonstrated. Different with a standard cavity design with
semiconductor saturable-absorber mirror (SESAM), self-starting mode-locking was initiated by stretching the length of
arm to reduce the beam spot, which shows the output beam possess higher beam quality than standard one. With a 10%
output coupler, we achieved 1 W output power and 21 ps pulse duration at pump power of 4.5 W. High efficiency and
high beam quality show the merit of the ps-laser.
Self-phase modulation of an ultra-short laser pulse from laser breakdown plasma
Yongsheng Zhang,
Lixin Yan,
Guoxin Zheng,
et al.
Show abstract
The detailed dynamic of an atom in a laser field with strength comparable to the atomic electric field is rich in physics
and potential applications. Laser-breakdown plasma-induced spectral shifting in supersonic rare gases jet has been
investigated with a sub-picosecond KrF excimer laser focused to peak intensity in the region of 1015W/cm2. A 1.4mm
diameter gas jet target was used in the experiment to minimize the refraction of the laser beam and thus a well-defined
focused region was obtained. The typical quasi-periodic spectral shifting structures for helium and argon have been
measured at various gas densities. For gas densities below 1x1020cm-3,both spectral red-shift and blue-shift were
observed, indicating the gas is partially ionized, in contrast to the predominantly blue shifted as the gas densities grows
high and fully ionized. Compared to the other ultra-short pulse measurement methods, qualitative information about the
pulse can be deduced by observing their spectrum after interacting with rare gas.
Self-starting mode-locked Cr: forsterite laser pumped by 1030 nm Yb: YAG laser
Binbin Zhou,
Peng Wang,
Yu Cang,
et al.
Show abstract
We report a self-starting mode-locked Cr:forsterite laser with 1030 nm Yb:YAG laser as the pump laser in this paper. Two chirped mirrors are used to provide the negative intracavity group-delay dispersion; the mode locking is initiated and stabilized by a semiconductor saturable-absorber mirror (SESAM). With absorbed power of 7W at 1030nm, stable femosecond laser pulses with average power of 202 mW were obtained at a repetition rate of 82.6 MHz, the autocorrelation measurement shows the typical pulse duration is about 29 fs.
Stabilization and phase control of femtosecond Ti:sapphire laser with a repetition rate of 90MHz
Wei Zhang,
Hainian Han,
Peng Wang,
et al.
Show abstract
Carrier-enveloped phase controlled femtosecond laser has an important application in the absolute frequency
measurement, which lead to a revolutionary progress in the frequency metrology. In this paper we will report a high
stable optical frequency comb based on a 90MHz repetition rate Ti:sapphire laser, by using a photonic crystal fiber to
broaden octave spanning spectrum and a self-reference technology to measure the offset frequency fceo, both the
repetition rate frep and fceo are locked simultaneously to a cesium clock with phase lock loop (PLL) technology. For
simultaneous stabilization of frep and fceo, two sets of phase-locked loop electronics are introduced to control separately the
laser cavity length for frep with a PZT and the pump laser for fceo with an acoustic optics modulation (AOM) respectively.
As the result, we stabilized the frep at a fluctuation within the order of μHz, and fceo is in the order of mHz, which support
a frequency comb with an uncertainty of 10-14.
Generation of 7-fs laser pulse and measurement of carrier-envelope phase by difference-frequency generation
Yanying Zhao,
Hainian Han,
Peng Wang,
et al.
Show abstract
An ultrabroaden spectrum covered from 600nm to 1000nm was directly generated from a self-designed femtosecond
laser. The laser resonator consists in only three or four chirped mirrors and one output coupler, we measured the pulse
duration is shorter than 7fs by compensating the dispersion outside the laser cavity, repetition rate of high as 160MHz
was realized. As our best knowledge, this is the simplest laser configuration of generating the pulse of shorter than 10fs.
To control the carrier-enveloped phase (CEP), we further used a PPLN crystal to generate the difference-frequency based
on the ultrabroaden spectrum, a beat frequency with signal to noise ratio of 34dB was observed. Locking the beat
frequency and the 160MHz repetiton rate to a Cs clock, it will enable us to realize a compact frequency comb with high
repetition rate.
Compression and carrier-envelope phase control of 5fs laser pulse for driving attosecond pulse
Jiangfeng Zhu,
Peng Wang,
Hainian Han,
et al.
Show abstract
A white light continuum of octave spanning was produced by self-phase modulation in a hollow-core fiber filled with
noble gases at high pressure and subsequently compressed by a set of ultra-broadband chirped mirrors. Pulses as short as
5.1 fs with energy up to 400 μJ at a 1 kHz repetition rate were obtained. Based on the carrier-envelope phase (CEP)
locking of the femtosecond oscillator and the spectral interference of the white light continuum between the white
fundamental wave and the harmonic wave at the same wavelength, the CEP of 5.1 fs pulse can be further locked by
modulating the pump laser through a slow loop. The intense, few-cycle laser pulses with a stable CEP will enable us to
produce high-order harmonic X-ray laser by the interaction with a rare gas target, this may drive the individual
attosecond pulse generation.
Poster Session: Pulsed X-ray Sources and Radiography
X-ray spectra from weakly ionized linear molybdenum plasma
Show abstract
In the plasma flash x-ray generator, a 200 nF condenser is charged up to 50 kV by a power supply, and flash x-rays are
produced by the discharging. The x-ray tube is a demountable triode with a trigger electrode, and the turbomolecular
pump evacuates air from the tube with a pressure of approximately 1 mPa. Target evaporation leads to the formation of
weakly ionized linear plasma, consisting of molybdenum ions and electrons, around the fine target. At a charging
voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the
peak current was about 17 kA. The K-series characteristic x-rays were clean and intense, and higher harmonic x-rays
were not observed. The x-ray pulse widths were approximately 600 ns, and the time-integrated x-ray intensity had a
value of approximately 2.0 mGy per pulse at 1.0 m from the x-ray source with a charging voltage of 50 kV.
High-sensitive radiography system utilizing a pulse x-ray generator and a night-vision CCD camera (MLX)
Show abstract
High-sensitive radiography system utilizing a kilohertz-range stroboscopic x-ray generator and a night-vision CCD
camera (MLX) is described. The x-ray generator consists of the following major components: a main controller, a
condenser unit with a Cockcroft-Walton circuit, and an x-ray tube unit in conjunction with a grid controller. The main
condenser of about 500 nF in the unit is charged up to 100 kV by the circuit, and the electric charges in the condenser
are discharged to the triode by the grid control circuit. The maximum tube current and the repetition rate are
approximately 0.5 A and 50 kHz, respectively. The x-ray pulse width ranges from 0.01 to 1.0 ms, and the maximum
shot number has a value of 32. At a charging voltage of 60 kV and a width of 1.0 ms, the x-ray intensity obtained
without filtering was 6.04 μGy at 1.0 m per pulse. In radiography, an object is exposed by the pulse x-ray generator,
and a radiogram is taken by an image intensifier. The image is intensified by the CCD camera, and a stop-motion
image is stored by a flash memory device using a trigger delay device. The image quality was improved with increases
in the x-ray duration, and a single-shot radiography was performed with durations of less than 1.0 ms.
Poster Session: Diagnosis of High-Temperature and High-Density Plasmas
Investigation of interaction of the plasma clouds forming as a result of two laser target irradiation
V. I. Annenkov,
A. V. Bessarab,
G. A. Bondarenko,
et al.
Show abstract
The results of investigation of two plasma clouds interaction appearing at the laser irradiation of two different targets in
background gas atmosphere on the MKV-4 facility of the "Iskra-5" has been described. The experimental data are
compared with the results of the theoretical simulation.
Experimental study on the flame behaviors of premixed methane/air mixture in horizontal rectangular ducts
Show abstract
In order to explore the flame propagation characteristics and tulip flame formation mechanism of premixed methane/air
mixture in horizontal rectangular ducts, the techniques of Schlieren and high-speed video camera are used to study the
flame behaviors of the premixed gases in a closed duct and opened one respectively, and the propagation characteristics
in both cases and the formation mechanism of the tulip flame are analyzed. The results show that, the propagation flame
in a closed duct is prior to form a tulip flame structure than that in an opened duct, and the tulip flame structure
formation in a closed duct is related to the flame propagation velocity decrease. The sharp decrease of the flame
propagation velocity is one of the reasons to the tulip flame formation, and the decrease of the flame propagation
velocity is due to the decrease of the burned product flow velocity mainly.
Optics-ammunition mechanism of plasma radiation inspired by exploding wires blasting in inert gases
Show abstract
We studied a new optics-ammunition mechanism by an adiabatic heating model of exploding wires on strong pulsed
current and a model of shock waves inspired by exploding wires blasting in inert gases. A Pspice simulation code for
engineering applications and an improved MHD (Magnetohydrodynamics) computation code for physics research have
developed in this paper. The computation results indicate that, firstly, plasma radiation intensity increased by Machnumber
of shock waves, and in all insert gases, argon's Mach-number of shock waves is highest. Secondly, silver is the
best in common metal materials, and the exploding time and current peak is about linear with the number of wires.
Thirdly, the parameters of wire including the diameter, length and number will influence the exploding performance
deeply; Fourthly, Pspice computation is an experiential method, but the result has direct guiding sense for engineering
design. Fifthly, the improved 1D single temperature MHD model can be used in multi-wire paralleled electricity
exploding computation very well, and computation results agree with the known experiment data and are important to
the study of strong pulsed IR optics-ammunition.
Optical imaging system for wire array Z-pinch on Qiangguang-I
Show abstract
A time-resolved optical imaging system is developed for "Qiangguang-I" generator to diagnose the early stage of wire
array Z-pinch. The optical imaging system is consisted by several independent modules. Each module includes a set of
object lens, an image intensifier, a set of relay lens and a CCD camera. The peak response of the system is at 439 nm.
The temporal resolution of the system is about 5ns, and the equivalent spatial resolution on the object plane is 6.5 lp/mm
when MTF=0.05. A series of images of 12mm diameter 32xΦ5μm tungsten wire array obtained by the system are shown
in this paper. We find that in the 32xΦ5 μm wire array experiments on "Qiangguang-I", from the implosion start to 60%
of implosion time, the behavior of single wire is dominant. The implosion time is (113±7) ns and the ratio of acceleration
time to implosion time ta/timp is about 0.60~0.75. The trailing mass distribution and the m=1 mode instability after the
stagnation phase are also observed in our experiments.
Poster Session: Ultrafast Lasers and Applications
Generation of short electrical pulses by photoconductive semiconductor switches triggered with a high-power laser diode
Show abstract
Microstrip line pulse generators based on gallium arsenide (GaAs) photoconductive semiconductor switches have been
fabricated and tested experimentally. The GaAs photoconductive semiconductor switches were optically triggered with a
70 W, 85 ns duration (FWHM) high power laser diode. Short electrical pulses have been obtained and reported with
practical applications emphasized. The risetimes and the durations of the output electric pulses can be less than 2 ns and
6 ns, respectively, which are in remarkable contrast to the 20 ns risetimes and the 85 ns durations of the activating optical
pulses.
Theoretical and numerical investigations of fused silica modification using ultrafast double-pulses
Show abstract
We study the mechanisms of ultrafast free-electron generation in laser-irradiated dielectrics (fused silica). The evolution
of the free-electron density in the conduction band of dielectrics irradiated by ultrafast double-pulses laser is calculated.
The effects of the avalanche ionization is calculated with the recently introduced multiple rate equation, which keeps
track of the energy distribution of the free electrons, while maintaining the conceptual and analytic simplicity of the
standard rate equation. Using temporally shaped pulse trains with picosecond separation leads to a significant
improvement in the quality of ultrafast laser micro-structuring of dielectrics. The evolution of the free-electron density in
fused silica irradiated by tightly focused 100 fs laser double-pulses at a center wavelength of 800 nm are numerically
investigated to study the role of nonlinear photo-ionization and avalanche ionization processes in free electron generation.
The role of impact ionization as compared to photoionization is analyzed.
Fast photomultiplier tube gating system for underwater laser detector
Show abstract
Laser will attenuate during its propagation in water and also be backward scattered by water when it is used to detect
bubbles in the ocean. Meanwhile backward scattering intensity of the bubbles is feeble, its dynamic range reaches to the
order of 6, which saturates PMT and its post-treatment circuit. Timely gating system is used to solve the problem. The
system contains pulsed laser and gating PMT receiver. The wavelength of the laser is 532nm, with pulse width of several
nanometers. Its operational delay is matched with the time period between laser traveling forward and back after
scattered by the target. By doing this, the light scattered by other object is eliminated, dynamic range of the signal
reduces, and consequently SNR increases. In order to avoid Signal Induced Noise(SIN), we choose PMT R1333 having
no HA coating. TTL logical level, which is used as gating signal, controls the first dynode voltage of PMT to implement
gating. Gating speed is about 100ns, of which the width is tunable. By carefully designing the electronic system, SNR is
eliminated to a level as low as possible, and the output signal of PMT is fast integrated in order to reduce the influences
of signal induced by opening the gate.
Laser induced defect damage on optical thin film
Show abstract
Interaction of laser irradiation with coating defects is studied in this paper. For microdefect, sphere impurity defect
model is employed to explain the breakdown process of optical thin film. For sub-microdefect, avalanche ionization by
nonlinear absorption is main way to lead thin film breakdown. To testify the effect of defect on the damage of thin film,
HfO2 thin films were deposited by the electron-beam evaporation method. The weak absorption and laser induced
damage threshold (LIDT) of thin film samples were measured, the damage morphology and defect density of samples
were also mapped by Nomarski microscope. These results indicated that the kind of damage morphology of thin film is
found to be typically defects initiated. The damage of every sample originates from defects and the damage enlarges
from the point of defects. It was also found that the absorption of the films would increase and the LIDT would decrease
with the increase of defect density.
Research on the stable state distribution of femetosecond pulses optical soliton communication system
Show abstract
With the high-speeding development of the ultrashort laser pulses techniques, the stability of the soliton propagating in
the dispersion-shift fiber has been becoming the topic in high speed optical communication system. From the nonlinear
Schrödinger equation, in this paper we discuss a quasi soliton specific solution without distortion which has the stable
propagating property, then simulate the waveform about these quasi solitons numerically, and more, by modifying the
structure parameters of the fiber the width of these quasi soliton pulse can be adjusted and the soliton communication
system can be optimized finally.
Laser-induced acoustic landmine detection with YAG and erbium fiber laser
Show abstract
Acoustic landmine detection (ALD) is a technique for the detection of buried landmines including non-metal mines. An
important issue in ALD is the acoustic excitation of the soil. Laser excitation is promising for complete standoff
detection using lasers for excitation and monitoring. Our method is based on a YAG laser at 1.06 um not He-Ne laser or
loudspeaker with acoustic excitation and on an erbium fiber laser at 1.54 um not microphone with LDV detection. An
analysis is given to show the potential and the inherent limitations of the technique. In the present paper we have tried to
answer two questions on locating landmines: (1) too many false alarm; (2) plastic landmine. The answer to the first
question is the LDV with an erbium fiber laser at 1.54 um. The second answer is YAG laser at 1.06 um induce acoustic.
Compensation of high-order phase distortions in chirped-pulse amplification system
Show abstract
Chirped-pulse amplification (CPA) technique has been widely used to generate ultra-intense femto-second pulses. In this
scheme the seed pulses from an oscillator are stretched before amplification. The stretched pulses can support more
energy extraction and effectively decrease the nonlinear effects in the gain media. The subsequent amplification in a CPA
chain will result in a broadening of the output compressed pulses in temporal domain due to the gain narrowing and
uncompensated phase distortions. In our experiment, using spectral modulation and phase pre-compensation system
(Acoustic-Optics Programmable Dispersive Filter) between the oscillator and the stretcher, the effects of gain narrowing
and high-order dispersions on the pulse duration in kHz chirped-pulse amplification system have been pre-compensated,
and the spectral FWHM is expanded from 30nm to 50nm. The effects of GDD, TOD and FOD were investigated by
scanning the four dispersion parameters respectively. By pre-compensating the high-order phase distortions with the
phase measured by SPIDER, we successfully optimize the output duration from 51fs to 30fs, which is 1.07 times
Fourier-transform-limitation.
Multi-pulse operation of Yb3+-doped fiber mode-locked laser
Show abstract
The multi-pulse operation of the Yb3+-doped fiber mode-locked laser with a polarization sensitive isolator and two
polarization controllers is reported. Dual- and triple-pulse of the Yb3+-doped fiber mode-locked laser in the normal
dispersion are achieved as the pumping power is increased. The fiber laser can achieve different multi-pulse outputs by
adjusting the polarization controllers or increasing the pump power. The results show that over-driving of the fast
artificial saturable absorber induced the generation of the multi-pulse.
Numerical study on the propagating performance of super-Gaussian ultra-short optical pulse
Show abstract
When an optical pulse with super-Gaussian shape is transmitted in fiber, it will gradually evolve to Gaussian function
shape under suffered all kinds of effects, such as group velocity dispersion (GVD), third order dispersion (TOD), forth
order dispersion (FOD), and nonlinear effects. An interesting phenomenon is observed, that is, TOD will transfer energy
of super-Gaussian pulse from one half to another within total flat top, but TOD will split Gaussian optical pulse and bring
strong oscillation structure in the edge of pulse. Corresponding to frequency domain, super-Gaussian pulse has two
evident slide slobs arranged in both sides of main peak, but TOD can make slobs fade away and transform frequency
spectral to Gaussian function shape. In a densely dispersion managed (DDM) fiber system, the propagation performance
of super Gaussian pulse with sub-picosecond pulse width is investigated. From clear eye-diagram of propagating over
1000 km, we can conclude that the DDM fiber system is very suitable for super Gaussian optical pulse transmission
under low system power condition.
Near-field optical characteristics of sub-wavelength grating irradiated by ultra-short optical pulse
Pinghe Zhou,
Ying Guo,
Feng Pan,
et al.
Show abstract
We present a method for near-field analysis of ultra-short optical pulse propagation in the sub-wavelength grating based
on the integration of Fourier spectrum decomposition and Fourier modal method. By using this method, near-field
optical distribution within a high-efficiency reflective grating based on total internal reflection (TIR) is calculated as the
irradiation source is a 200fs optical pulse with central wavelength of 1053nm. Electric field enhancement within the TIR
grating is analyzed for both TE- and TM-polarized pulses. Methods of controlling the peak intensity in the grating ridge
are also presented.
Passive Q-switched fiber laser with SESAM in ytterbium-doped double-clad fiber
Show abstract
A passively Q-switched ytterbium-doped double-clad fiber laser with SESAM as a saturable absorber is demonstrated
experimentally. This system showed up to 18.7mW output power, up to 29.4 kHz repetition rate, a maximum pulse
energy of 0.636μJ and a minimum pulse duration of 3.148 μs. The characteristics of pulse were investigated, and the
theoretical analysis agree well with the experimental results.
Experimental study on laser ablating different materials in atmosphere
Show abstract
In order to investigate the laser ablation propulsion property of different materials in atmosphere, experiments are
conducted, with a Nd:YAG passive Q-switch solid laser (single pulse energy 66mJ, pulse width 70ns) as energy source,
black rubber, gray PVC, brass and SiC as testing materials. As results, the momentum coupling coefficients of the
measured materials rise first and then fall with the increase of laser power density, which agrees with the observation of
aluminum in vacuum. Among the tested materials gray PVC shows the lowest plasma ignition threshold, which is
0.86x108w/cm2, and highest momentum coupling coefficient, which is 11.83dyne/w.
Poster Session: High-Speed Holography and Interferometer
A differential interferometer with the four-focus imaging system
Show abstract
A new type of differential interferometer was created by placing the ring cavity of a cyclic lateral shearing interferometer
between two lenses of a four-focus imaging system. The four-focus system is slightly defocused by adding an offset
between the object plane and the front focal plane of the first lens. The shear distance of images varies directly as both
the offset and the shear distance of the cyclic interferometer. The spatial carrier frequency of fringes varies directly as the
shear distance of the cyclic interferometer, but it is independent of the offset. Thus the dependence between the carrier
frequency and the shear distance of images is broken and it's possible to adjust them respectively. Furthermore, this
differential interferometer is also very stable, which is important when vibrations can't be avoided in experiments. The
interferometer has been applied to diagnostics of plasma with large density gradient.
A new real-time surface profile measurement using a sinusoidal phase modulating interferometry
Show abstract
In this paper, a sinusoidal phase modulating interferometer has been proposed to realize real-time surface profile
measurement. And its operation principle has been analyzed theoretically. By analyzing the interference signal through
the signal processing circuit, the displacement of each point on the surface can be obtained. The experimental results by
using this interferometer to measure a glass plate show the maximum root-mean-square is 5.2nm, and the displacement
resolution is up to 5x10-3nm.This method proposed in this paper avoids the complex phase demodulation by computer,
has high measurement accuracy, and can be used in the noise circumstance.
Research of transient flow field real time interferogram acquisition system
Show abstract
This paper describes a novel synchronous control system of high speed imaging, which combines a common path
interferometer system modulated by the space phase. The system can continuously grab multiple frame interferograms,
which contain transient flow field distortion. The study of this system will provide a fire-new means for the research of
aerodynamics. The light source of the system is Nd: YLF semiconductor pump solid pulsed laser of which wavelength is
1053 nanometers. The laser pulse width is less than 30 nanoseconds, far less than the exposure time of the camera
shutter. Thus the laser pulse can freeze the flow field within several dozen nanoseconds and catch the biggish change of
turbulent flow. The pulsed laser beam containing the information of turbulent flow enters a cyclical radial shearing
interferometer. The emergent lights, being respectively contracted and expanded, re-combine and form fringe pattern in
high space frequency, modulated with a definite carrier frequency. The fringe pattern is formed on the high speed CMOS
camera at last. An accurate short time delay circuit is provided for synchronization matching of the pulsed laser and
camera exposure. The speed of image acquisition in full pixels with 1280×1024 can reach 450 frames per second. This
interferogram acquisition system with compact configuration and strong anti-disturbance capability, has successfully
grabbed clear transient interferograms that provided reliable image information for follow-up image processing and flow
field density calculating.
Research on optical interferometric communication frequency characteristic test and matching method
Li-Li Guo,
Yi Wang,
Ke-jia Wang
Show abstract
The paper proposes a laser light source and component frequency characteristic test and match design scheme based on
space laser communication of optical interferometric heterodyne detection. The scheme utilizes dual phase-shifted fiber
gratings to modulate frequency when the interferometric light of different frequency pass photoconductive photodetector
weeny light heterodyne frequency switch highly electronic frequency and proceed to frequency response test and
matching. We can proceed to match design of total system optical frequency characteristic according as component
frequency characteristic matching adjustment. Compared with conventional scheme that the variety of regulable optical
cavity length obtains beat frequency signal in the photoconductive photodetector, the scheme can proceed to exceed
broad band frequency response characteristic test to photoconductive photodetector and total communication system
without additional calibrate light source and the scheme possess quantitative control and narrow line breadth of laser
signal less polarization so that highly precision of test and distinguishability. The scheme significantly improves anti-jamming
performance of optical communication system and advances a novel method in the test and matching design of
optical communication laser frequency characteristic.
Observation and research of chip formation and efflux by high speed hard cutting
Show abstract
This paper observed the chip forming and effusing process when high speed hard turning hardened steel using PCBN
tools under two-dimensional longitudinal turning and transverse turning by high-speed photography, and obtained the
chip formation and efflux states with different cutting edge preparation and parameters. The experiment results showed
that the sharp-edged tool was useful for chip forming, but strength of its edge is low and the tool life is short, and that the
tool has longer life under the chamfered edge, but too small or too large cutting thickness goes against the chip forming
and effusing.
An adaptive mean shift particle filter for moving objects tracking
Xun Wang,
Yufei Zha,
Duyan Bi
Show abstract
In this paper, we integrate mean shift algorithm into the particle filter as the proposal distribution, and adaptively modify
the tracking step according to the process of mean shift algorithm. It can be used through the searching for the most
matching region with the feature, such as color, texture, etc, which should first be drawn from the targets. Experiments
show that it is an efficient and powerful method for tracking fast moving objects in clutter even with occlusions.
Moving airplane real-time detecting based on lifting wavelets
Jianhua Wu,
Wenhua Qiu,
Ping Wang
Show abstract
Moving objects detecting is one of the most important tasks in a lot of fields like robot vision, video information
processing. A moving plane detecting method based on lifting-wavelets is introduced in this paper in order to improve
the performance in the aspects of nicety and real-time. In the detecting process, we have taken full advantages of the
characteristics of multi-resolution and the merit that lifting frame can be designed in time and frequency fields.
Experimental results show that this method can increase the detecting efficiency effectively in different cases where the
background is complicated and artificial objects are greatly different. The detecting capabilities would not be affected by
the condition of moving objects. This method has good robustness and can remove noise well at the same time.
Research on applications of optical wavelet transform in high-speed photograph
Tao Wang,
Dongmei Li,
Chunkuang Tao,
et al.
Show abstract
Image and data are always needed to be processed and analyzed at real time during high-speed photograph, so high
processing speed is required. As the optical wavelet transform utilizes the parallel computation of optical elements, it has
a high transform speed. Hence it can be used for image processing and analysis during high-speed photograph. The
light-path structure and principle of optical wavelet transform is introduced in this paper. It is realized by using 4f optical
information processing system. And the methods for realizing pattern recognition, image feature extraction, image edge
enhancement etc. are given. Specially, the requirements on light source, light-path structure, optical elements and filter
of optical system are analyzed when optical wavelet transform is used for image compression. And some improved
measurements are put forward according to present problems. Firstly, the merits of using white light information
processing system for image compression is analyzed. Secondly, adopt liquid crystal light valve and spatial light
modulator to strengthen flexibility and practicability. Thirdly, the method of determining focuses of lens and how to use
Talbot effect to locate the object plane and spectrum plane are given. Finally, the use of reflecting 4f system is put
forward to decrease chromatic aberration and noise in optical wavelet transform. And we have obtained some
experimental results which are good for further research.
Dynamic monitoring studies for high speed mechanical manufacturing process
Yonghong Zhang,
Lihua Wang,
Qi Wu,
et al.
Show abstract
The high-speed image sampling based on CCD camera was used monitoring abrasive machining and boring machining
respectively in this paper. The two monitoring system organization and their principles of operation were introduced in
detail. The transient images of grinding wheel or boring cutter nose were sampled at certain positions, which were
detected by sensors. Mathematical derivation was analyzed and gave relationship of influencing factors. From some
experiments, it can be seen that the monitoring method based on CCD camera is effective and real-time.
Free-surface velocity measurements using an optically recording velocity interferometer
Jian-xin Lu,
Zhao Wang,
Jing Liang,
et al.
Show abstract
An optically recording velocity interferometer system (ORVIS) was developed for the free-surface velocity
measurements in the equation of state experiments. The time history of free-surface velocity and the particle velocity in
laser deduced shockwaves experiments can be recorded by the electronic streak camera in ORVIS. The interference
fringe shifts recorded by the ORVIS is proportional to the Doppler shift of a laser beam induced by being reflected from
the back suface of the monitored target. In the experiments, ORVIS got an 179 ps time resolution, and a higher time
resolution could be got by minimizing the delay time. The equation of state experiments were carried out on the high
power excimer laser system called "Heaven I", the velocity of iron and aluminium was researched.
Study of high speed photography measuring instrument
Show abstract
High speed photograph measuring instrument is mainly used to measure and track the exterior ballistics, which can
measure the flying position of the missile in the initial phase and trajectory. A new high speed photograph measuring
instrument is presented in this paper. High speed photography measuring system records the parameters of object
real-time, and then acquires the flying position and trajectory data of the missile in the initial phase. The detection
distance of high speed photography is more than 4.5km, and the least detection distance is 450m, under the condition of
well-balanced angular velocity and angular acceleration, program pilot track error less than 5'. This instrument also can
measure and record the flying trail and trajectory parameters of plane's aero naval missile.
A servo-control system for detecting micro-displacement based on interferometry
Jianhua Hui,
Yongying Yang,
Jiao Liang,
et al.
Show abstract
Enhancing the measurement precision of the micro-displacement has become a significant trend of modern technology.
This paper describes a servo-control system that can detect the displacement up to the order of nanometer on the basis of
interference and resonance intensifying. The micro-displacement variance of a sample would cause the amplitude change
of the microprobe, vibrating at the resonance frequency. By a point-diffraction-interference system, the amplitude
change can converted to electrical signal after the photodiode detector. Then, this signal is sent to the feedback control
system with PID model. Amplified by the high-voltage circuit, the feedback signal drives the piezoelectric crystal under
the sample working stage to flex, keeping the distance constant between the microprobe and the sample. The circuit
design possesses compact structure, good noise resistance and high stability. Apply this system to an atomic force
microscope (AFM) to scan the sample surface coating aluminum fluoride. The results show that under the condition of
100 kHz resonance frequency, the image quality of sample's microscale topography with this servo-control system is
evidently better than that with open-loop system. The operation only costs dozens of seconds to finish scanning 400×400
points and the precision is better than the order of nanometer.
Moving object detection under complex background using radial basis function neural network
Zuomei Lai,
Jingru Wang,
Qiheng Zhang
Show abstract
It is well known that moving object detection under complex background becomes more difficult because of moving cameras. According to the fact that background and objects have different motion, the moving scene can be decomposed into different regions with respect to their motion by means of a radial basis function(RBF) learning scheme. After global background motion compensation, five-dimensional (5-D) feature vectors include pixel intensities, current pixel coordinates and pixel dense optical flow field extracted from image sequences are treated as the inputs of the RBF network. The learning algorithm for the network minimizes a cost function derived from the Bayesian estimation theory. Each output unit of the network is associated to a moving object. Experimental results indicate the algorithm's validity after many complex sequences are tested.
The measurement of micro-topography surface based on wave cutting interference theory
Mei Hui,
Nian-mao Deng
Show abstract
This paper proposes the measurement of micro-topography surface based on wave cutting interference theory. This wave
cutting interference system realized the differential cutting and complex polarization with beam splitter polarize prism.
Math model is established based on matrix analysis. The phase distribution is obtained with equation between intensity
and phase from the figure of the light intensity information, the value of micro-topography surface is obtained after data
manipulation. Some technical difficulties existed in the surface microscopy are analyzed and solved.
Source rock maturity study by capillary tube interferometer
Show abstract
The mechanism of capillary tube interferometer is expected to be two-beam interference by ray tracing. A computer
program to simulate the interference fringe pattern was established. By comparing the simulated fringe pattern and
experimental fringe pattern, the refractive index of the liquid can be given when the two fringes coincide best. The
results of this method are very near the Abbe refratometer.
In the first time, the refractive indices of the low transparent extraction of source rocks were measured by capillary tube
interferometer. A curve between the refractive indices of the diluted extraction of source rocks and corresponding
vitrinite reflectance Ro was established. When Ro is in the range of 0.36-1.25, the refractive indices of the extraction
increase with Ro, or the maturity of the source rocks. Good correlation was observed between the refractive indices and
vitrinite reflectance Ro. The refractive index of the extraction of source rock is valuable for determining the degree of
maturity of source rock. This technique is promising to measure the refractive indices of low transparent liquids and
could be used to estimate the maturity of source rock.
Applications of high-speed motion analysis sytem on Solid Rocket Motor (SRM)
Show abstract
High-speed motion analysis system could record images up to 12,000fps and analyzed with the image processing system.
The system stored data and images directly in electronic memory convenient for managing and analyzing. The high-speed
motion analysis system and the X-ray radiography system were established the high-speed real-time X-ray
radiography system, which could diagnose and measure the dynamic and high-speed process in opaque. The image
processing software was developed for improve quality of the original image for acquiring more precise information.
The typical applications of high-speed motion analysis system on solid rocket motor (SRM) were introduced in the
paper. The research of anomalous combustion of solid propellant grain with defects, real-time measurement experiment
of insulator eroding, explosion incision process of motor, structure and wave character of plume during the process of
ignition and flameout, measurement of end burning of solid propellant, measurement of flame front and compatibility
between airplane and missile during the missile launching were carried out using high-speed motion analysis system.
The significative results were achieved through the research. Aim at application of high-speed motion analysis system on
solid rocket motor, the key problem, such as motor vibrancy, electrical source instability, geometry aberrance, and yawp
disturbance, which damaged the image quality, was solved. The image processing software was developed which
improved the capability of measuring the characteristic of image. The experimental results showed that the system was a
powerful facility to study instantaneous and high-speed process in solid rocket motor. With the development of the
image processing technique, the capability of high-speed motion analysis system was enhanced.
High-speed phase shifting profilometry with dual-frequency digital projection grating pattern
Show abstract
An investigation of optical shape and profile measurement technique with respect to dual-frequency digital projection
grating pattern is presented in this paper. Two gratings with different frequencies are respectively projected onto an
object for the extension of the unambiguity range. And then, grating patterns which are deformed according to the object
shape are acquired by a CCD camera. The 3D shape of object surface is reconstructed by using
dual-frequency-combination phase-shifting profilometry (PSP) algorithm which is especially presented. Several
advantages of using new algorithm instead of other traditional approaches are adequately discussed in practical
measurement. Comparing to either conventional PSP or dual frequency PSP, dual-frequency-combination PSP has
speediness advantage because of no phase unwrapping process and other additive processes. Furthermore, the analysis
proves that the variance of phase in dual-frequency-combination PSP is much steadier than that in dual-frequency PSP.
Finally experimental results demonstrated the feasibility of this technique for high-speed surface profile measurement.
Projected fringe profilometry of a high speed moving object using a time delay and integration imaging
Show abstract
A novel technique is presented for measurement of surface profile, dynamic inspection of surface quality and
nondestructive detection of a motion object at highly constant speed in this paper. In practice, a sinusoidal grating pattern
with a common LCD projector is projected onto a moving object. Then, grating patterns which are deformed according
to the object shape are acquired by a CCD camera operating in time delay and integration (TDI) mode. When the charges
in TDI camera are shifted row by row at a specified speed which is the same as the object speed, a clear and bright image
is easily obtained. Because of this advantage in the application of TDI camera, it is proved to be an effective and
straightforward approach to avoid blurred image in high speed 3D projection grating patterns profilometry. In our
experiment, Fourier transform algorithm is used for projected fringe profilometry. Upon that, absolute 3D surface profile
is perfectly achieved. Finally, several factors which will induce measurement errors are respectively discussed, such as
the speed disharmony between the object and TDI charges transfer and orientation disorder between the fringe pattern
and motion object.
Poster Session: High-Speed Video Technique
Design of underwater video attached to buoy for observing shallow water substrate
Show abstract
Knowledge of shallow water substrate is very important for protection and management of coastal ecosystem.
Traditional methods for observing shallow water substrate was by sending diver to photography and recorded with eye,
which was laborious and money taking. In order to obtain the easier way to study the shallow water substrate, an
underwater video system was designed. Underwater video sensor, optical sensor, sonar sensor, tiltometer, GPS system,
and ascending and descending system were all attached to the buoy system, and data was gathered and processed by the
computer on the ship. The obtained data could be used for analyzing substrate type, activity of benthos and ground truth
data for satellite remote sensing.
Motion detection and estimation in low-level-light video sequence
Show abstract
This article introduces motion detection and estimation of low-level-light video sequence, and, motion detection, motion
estimation and variational problem. Low-level-light video sequence different form others, the time and space domain
noise in the signal not only limit the lowest illuminance of the system but also make the image show random glitter. In
this paper how to improve the signal-to-noise ratio (SNR) of low light level image is discussed too. The results show that
models and estimation algorithms in low-level-light video sequence can lead to improve reliability and accuracy of the
estimated motion.
Research on a robot landmark localization system based on monocular camera
Yuan Luo,
Xiaodong Xu,
Yi Zhang
Show abstract
Robot localization is very important for the researching of intelligent robotics. The accurate of the robot coordinate will
influence the control accuracy of the robot's moving action. So, it is essential for robot itself to have the ability to realize
the modifying of coordinate of its own in real time when it is moving. In this paper, a robot landmark localization system
based on a monocular camera is researched theoretical and experimental. Three longitudinal landmarks are used to
assure the robust of the system. Digital image processing technology is enrolled to revise the image stretching and
decrease the disturbing of noise. The experiments based on Pioneer III mobile robot show that this system can work well
at different topographic situation without lose of signposts.
A new method of glare protection on highway real-time monitoring during nighttime
Show abstract
When car run in highway during night, need switch on its headlight, for intensity of the light is very high, it will cause
glare vision, the camera of monitoring system will be saturation, and all the other detail (For example: License plate)
can't be shown on the screen except headlight and its glare. In this paper, introduce a new system and method of glare
protection on highway nighttime monitoring, it can decrease the intensity of headlight and the glare vision in real-time,
so the monitoring system could gain more details of highway from camera. The whole system's hardware is made up of
outer camera-lens, inner camera-lens, spatial light modulator array and image sensor. The outer camera-lens images the
objects (cars on highway) on the plane of the spatial light modulator array's panel. So, the spatial light modulator array
can modulate part of the image on its panel, such as decrease or increase transmission ratio (or reflect ratio). The inner
camera-lens images the spatial light modulator array's panel to the image sensor. So, the image on the image sensor is the
image of object image after modulated. After the image sensor gained the image, we will use our software to analyze the
image, use real-time processing to get the saturation and glared region. Firstly, we use threshold arithmetic to get the
saturation and high intensive pixels of the image; secondly, we use filter to get ride of the noise made from threshold
arithmetic, so we can get the region of saturation and glare region of the original image; thirdly, we do expand arithmetic
at the direction of car's moving, and feedback the image to spatial light modulator. If we don't use expand arithmetic at
the direction of car's moving, and feedback the image gained after step 2, for the car in highway is moving very fast,
after the time of image processing, the car has moved to a new location with it's direction, so the feedback image will not
decrease the light intensity of the car's headlight and it's glare region properly. For these three processes are decreasing
the intensity of the image region, we called it negative feedback. At same time, we do positive feedback to increase the
transmission ratio (or reflect ratio) at the low light intensity region, so that more details of the object will be imaging on
image sensor. In fact, the image feedback on the spatial light modulator array is the composite of the negative feedback
and positive feedback. In experiment, the spatial light modulator array is liquid crystal on silicon (LCoS), all image
processing is on computer, the feedback image transfers via DVI bus. For the limit of operation system, the feedback
time is about 100ms.
Automatic moving object segmentation in video sequence
Xiaoyan Zhang,
Yuguo Dong,
Xuchun Zhuang
Show abstract
A novel algorithm for automatic segmentation of moving objects from video sequences is proposed in this paper. Firstly,
a fourth-orders statistic hypothesis testing in inter-frame difference is used to automatically separate the moving areas
from the background in a general video sequence. Then the morphological filter is used to remove the noises and holes.
Secondly, for three consecutive frames, superposition of the moving areas of first and second frame and that of second
and third frame highlights the moving object areas of the second frame, the covered/uncovered background may be
eliminated using such idea. Thirdly, the initial contour of the moving objects is determined by extracting the contour of
the moving object areas and an improved active contour which uses the gradient vector as the external force guides the
initial contour moving to the accurate moving object contour. Lastly, the motion compensation which uses the new three-step
search algorithm is made to the moving object contour to obtain the initial contour of the next frame and the
improved active contour is used again to correct the moving object contour of the next frame. Thus, following frames
segmentation can be realized. Experiment testifies that the proposed algorithm is of few parameters, robust to noise and
best in result of segmentation.
A novel mobile robot localization based on vision
Show abstract
It is very important for mobile robot to correctly and fleetly locate. With the development of the theory and arithmetic of
computer vision, vision navigation has become an important research direction in airmanship of mobile robot. In the
paper, localization based on landmark is researched by using the camera of mobile robot on the basis of traditional
localization method. A novel mobile robot localization based on vision is presented by using multi-sensor data fusion. It
is showed from experiment data that the new localization method has better performance.
Design and implement of infrared small target real-time detection system based on pipeline technology
Lihui Sun,
Yongzhong Wang,
Yongqiang He
Show abstract
The detection for motive small target in infrared image sequence has become a hot topic nowadays. Background
suppress algorithm based on minim gradient median filter and temporal recursion target detection algorithm are
introduced. On the basis of contents previously mentioned, a four stages pipeline structure infrared small target detection
process system, which aims at characters of algorithm complexity, large amounts of data to process, high frame
frequency and exigent real-time character in this kind of application, is designed and implemented. The logical structure
of the system was introduced and the function and signals flows are programmed. The system is composed of two FPGA
chips and two DSP chips of TI. According to the function of each part, the system is divided into image preprocess stage,
target detection stage, track relation stage and image output stage. The experiment of running algorithms on the system
presented in this paper proved that the system could meet acquisition and process of 50Hz 240x320 digital image and the
system could real time detect small target with a signal-noise ratio more than 3 reliably. The system achieves the
characters of large amount of memory, high real-time processing, excellent extension and favorable interactive interface.
An approach of fast image mosaic based on binary region segmentation
Show abstract
An approach of fast image mosaic is presented, which involves image matching and image intensity smoothing. Image
matching includes two procedures, i.e. rough matching and fine matching. In rough matching, the overlapped regions of
two adjacent images to be mosaicked are segmented to binary image at first. Then the binary images are filtered by open
operation of mathematic morphologic method. In the binary image region of the reference image, feature template is
searched and extracted on a given rule. Via XOR operation of the feature template and search region, some possible
matching positions in the overlapped region of the other image are got. In the fine matching, the sequential similarity
detection algorithm (SSDA) is adopted to perform matching computation in the small regions near the positions got in
the rough matching, and then the relative position offsets in X-orientation and Y-orientation between the two adjacent
images are got. Based on the result of the image matching, the two images are stitched. An approach of seam-line
smoothing is adopted to adjust the intensity of the overlapped area. Simulation experimental results show that the
approach greatly improves the operation speed, while the precision remains fine, so it can be applied in real-time
mosaicking.
Real time recognition target under complicated background by using Vander Lugt correlator
Show abstract
An approach of in-situ measuring the complex response of a scene spatial light modulator which working in differential
state was presented by using an image of Ronchi grating substituted for a concrete one. Its principle and testing method
have been studied and a typical XGA2L11 spatial light modulator has been characterized. The scene image under
complicated background has been edge enhanced by mapping the measurement results, and the correlation results
showed that scene spatial modulator with the differential state can increase the SNR and PCE of correlation peak. The
way could be wholly applied in Vander Lugt Correlator and has very strong practicability and effectiveness.
Rotation-canceling real time system of color video image
Shengxiang Tao,
Wei Ma,
Lizhi Qian
Show abstract
The paper puts forward an electronic rotation-canceling method based on high-speed DSP. The method adopts the
rotation algorithm to counter rotate quantum components of luminance and chrominance for the image of each field, and
then use the linear interpolation to resample and output pixels, thus realizing real time rotation-canceling of color video
image.
State-space blur model for high-speed forward-moving imaging system and its recursive restoration
Show abstract
When an imaging system is approaching the object at a high speed, because of the existence of integration time, the
images obtained are always blurred radially. Since the degradation process is space variant, this kind of blur is difficult to
handle, traditional frequency domain techniques can't be applied here. Obviously, the radially blurred image obtained is
rotation symmetrical, so the usual uniformly sampled image can be resampled with fan-shaped grids, and the gray level
of these new sampling points build up a new image matrix. The new image matrix's columns and rows are never the
edges of the image, but the image's radius and angle. So, the original two-dimensional problem is simplified. Even after
the resampling, the blur is still space variant, and the PSF (point spread function) will change along the radius direction.
So the authors come up with a state-space method, a state-space blur model is constructed, which handles the problem
recursively. To restore the degraded image simply means to find the inverse of the degradation system and computer
simulation result shows the restoration algorithm restored the radially blurred image approvingly.
Detection of small moving targets in staring images sequence with complex background and low contrast
Show abstract
A detection algorithm for small moving targets is proposed. The new algorithm firstly utilizes convolution filtering for
noise smoothing, and then a proposed preprocessing method based on the norm of the difference vectors of the processed
images sequence is applied to remove most of low-frequency background. Furthermore, optic flow technique is adopted
to segment the doubtful small moving targets from the subimage remained by preprocessing. Finally, the statistic
information for each of doubtful small moving targets is calculated. From the statistical feature, a determining criterion is
established to determine whether each of the doubtful small moving targets is a true target or not. Because the
preprocessing approach can get rid of most of the low-frequency background effectively, the calculation quantity of the
sequential processing by optic flow is decreased largely. The experiments in a designed test system prove that the
proposed detection algorithm can detect small moving targets in 30fps, 512x512 pixels, staring images sequence with
SNR no less than 3dB, and the correct detecting probability is up to 96%, which can satisfy the real time processing
requirements in practice.
Poster Session: Diagnosis of Ultrafast Phenomena
High-speed diagnostic pulsewise-periodic of electric discharge in water
Victor A. Kolikov,
Mikhail E. Pinchuk,
Anatoly G. Leks,
et al.
Show abstract
The results of research of pulsewise-periodic discharge in a water with a periodic time from 10 Hz up to several kHz,
duration of discharge impulse 1-50 μs, current amplitude 10-100 A, current rise rate from 106 A/s to 108 A/s are
presented.
The optical diagnostic of electric discharge in a water is carried out by the high-speed miniature 9-frame image converter
camera K-011, one frame camera NanoGate-1 and the spectrograph with ICCD. The camera K-011 allows to register up
to 9 frames with an exposition up to 0.1 μs and time between frames up to 0.1 μs. The exposure time of NanoGate-1 is
up to 10 ns. The registration of spectra can be carried out with an exposition up to 5 ns. The program complex allows to
record of a series of discharge impulses.
The main discharge parameters was determined by this high-speed optical diagnostics: discharge channel temperature,
velocity of channel expansion, compression waves dynamic was determined. The feature of the channel formation were
detected in unipolar mode of discharge and in oscillate mode.
High-speed optical studies of the long sparks in very transient stages
Show abstract
High-speed optical studies of different stages of the long sparks have been carried out at the High Voltage Research
Center (HVRC), Istra, Russia, using up to three devices operated synchronously: two novel universal streak and framing
cameras K004M and K008 developed by the BIFO Company and an analog image converter streak camera of FER14-
type instrumented with a CCD readout system of SU04-type. Special attention was paid to the improved spatiotemporal
resolution when recording the pictures of large sizes. The measurements were conducted in rod-to-plane gap of 5.5÷6 m
in length under both polarities HV pulses of 2÷3 MV in altitude with waveform of 20/7500 and 100/7500 μs. Under
negative polarity, an additional thin metallic rod about of 1 m in length was placed on the grounded plane to provide an
origin of the positive upward leader and its reliable observation. The velocity of approaching the downward negative
streamer-leader system and upward positive leader toward each other near the junction point has been found to be around
5÷10 m/μs. Some supporting exemplary pictures have been recorded to additionally clarify the phenomenology of the
stepped or/and attempted leaders, which can be useful for analysis of long spark and lightning treeing and development.
High-speed velocity measurements on an EFI-system
Show abstract
For the development of an Exploding Foil Initiator for Insensitive Munitions applications the following topics are of
interest: the electrical circuit, the exploding foil, the velocity of the flyer, the driver explosive, the secondary flyer and
the acceptor explosive. Several parameters of the EFI have influences on the velocity of the flyer. To investigate these
parameters a Fabry-Perot Velocity Interferometer System (F-PVIS) has been used. The light to and from the flyer is
transported by a multimode fibre terminated with a GRIN-lens. By this method the velocity of very tiny objects (0.1
mm), can be measured. The velocity of flyer can be recorded with nanosecond resolution, depending on the Fabry-Perot
etalon and the streak camera. With this equipment the influence of the dimensions of the exploding foil and the flyer on
the velocity and the acceleration of the flyer are investigated. Also the integrity of the flyer during flight can be analyzed.
To characterize the explosive material, to be used as driver explosive in EFI's, the initiation behaviour of the explosive
has been investigated by taking pictures of the explosion with a high speed framing and streak camera. From these
pictures the initiation distance and the detonation behaviour of the explosive has been analyzed. Normally, the driver
explosive initiates the acceptor explosive (booster) by direct contact. This booster explosive is embedded in the main
charge of the munitions. The combination of initiator, booster explosive and main charge explosive is called the
detonation train. In this research the possibility of initiation of the booster by an intermediate flyer is investigated. This
secondary flyer can be made of different materials, like aluminium, steel and polyester with different sizes. With the aid
of the F-PVIS the acceleration of the secondary flyer is investigated. This reveals the influence of the thickness and
density of the flyer on the acceleration and final velocity. Under certain circumstances the flyer breaks up in several parts
and several velocities at the same time have been recorded. Several flyer materials and dimensions exist that are able to
initiate very insensitive explosives like TATB.
Femtosecond study of electron transfer dynamics of anionic-cationic cyanine dye J-aggregates to AgBrI microcrystals
Show abstract
Using femtosecond time-resolved upconversion fluorescence spectroscopy technology, the fluorescence decay properti-es of J-aggregates of anionic-cationic cyanine dye, anionic cyanine dye and cationic cyanine dye adsorbed on surfaces of the cubic AgBrI grains are investigated. The kinetics of the electron transfer and the spectral sensitization property are analyzed in detail. The experiment setup in our work is the fluorescence upconversion(also called fluorescence frequen-cy generation)spectrometer. The time-resolution reaches about 140 fs. Anionic-cationic cyanine dye studied in our ex-periment is new-type cyanine dye, which formed by anionic cyanine dye reacting with cationic cyanine dye.
By contrary of the sensitization performances of several cyanine dyes, It is found that the sensitization performance of cubic AgBrI sensitized by anionic-cationic dye is marked higher than those of anionic cyanine dye, cationic cyanine dye and the mixture of anionic cyanine dye and cationic cyanine dye. The fluorescence decay curves of cyanine dyes J-aggregates obtained by femtosecond fluorescence upconversion spectrometer are analyzed as a sum of double exponent-ials, and the fitting curves consist of a fast and a slow component. Because of the large amplitude, this fast decay should be mainly attributable to the electron transfer from dye J-aggregates to conduction band of AgBrI. The electron transfer velocity of anionic-cationic cyanine dye J-aggregates is larger than those of anionic cyanine dye, cationic cyanine dye and the mixture of anionic cyanine dye and cationic cyanine dye, which is consistent with the results of the sensitization performance and the photoelectron lifetime. Dye1 has higher sensitizing efficiency than other cyanine dyes on the cubic AgBrI grains.
Extracting protein folding kinetics in single-pair fluorescence resonance energy transfer experiment based on wavelet analysis
Show abstract
Dynamic structural changes of protein folding and biological macromolecules undergoing biochemical reactions can be
monitored and studied using the single-pair fluorescence resonance energy transfer (sp-FRET) spectroscopy tool. In this
work, we have simulated a single-pair FRET photoemission process as an illustrative model example, where a FRET pair
resides on a folding protein that undergoes diffusion in water. And then we apply the wavelet analysis method, which is a
widely used method in many fields, such as the digital signal processing, noise reduction and the data compression
(JPEG2000), to deal with the case of fluorescence resonance energy transfer (FRET) experiment for protein folding. It is
shown that the wavelet analysis filter facilitates the detection of various intermediate conformational states in a noisy
trajectory. Thus it is finally suggested that it is particularly suitable for sp-FRET spectroscopy studies of protein folding
and can be of use for directly extracting the folding energy landscape. Our study establishes potentially useful data
analysis technique and theoretical guidelines for the study of sp-FRET spectroscopy experiments.
Inversing chlorophyll-a concentration by multi-temporal models using TM images
Show abstract
Chlorophyll is a very important parameter for lake water quality evaluation. Its concentration varies seriously with
different season. The chlorophyll-a concentration inversing models in different season were studied using different
temporal TM images. The models were built in 3 steps: Firstly, 10 images were selected according to the principle of
almost synchronously with in situ measurement; secondly, remote sensing images were preprocessed. Atmospheric
corrections were carried out use 6S model, and then, the images were geometric corrected; lastly, the optimum models
for chlorophyll-a concentration inversing were discussed for multi-temporal TM images. The water quality parameters
were measured on 21 sample points in Tai Lake, China monthly as the monitoring network. The chlorophyll-a
concentration inversing models were built using semi-empirical approach by the integrated use of multi-temporal remote
sensing data and in situ data. The spectrum character of chlorophyll was analyzed following other's studying. Then the
different composed bands and component modes such as TM4/TM3, (TM4-TM3)/(TM4+TM3), TM3*TM4/ln(TM1), etc.
were discussed for building the regression models. The inversing accuracy was evaluated by relatively error. The
optimum models were selected for each month by comparing the different models. It could be concluded that: The mode
of multi-temporal equations might be the same or similar for different month. But the coefficients were quite different;
the reflectance of TM3 and TM2 band were the most often used parameter for model building; the estimated accuracy
increased with raising chlorophyll-a concentration. For example, when the chlorophyll-a concentration was lower than
0.009mg/l, the estimated value was not so accuracy. But when the chlorophyll-a concentration raised to 0.05mg/l the
relatively errors for all samples were less than 30%.
Poster Session: Sensors for High-Speed Diagnosis (CCD, CMOS, Etc.)
A new high-speed image sensing technique based on an ordinary CCD
Show abstract
In this paper, the reason of ordinary CCD's low frame rate was analyzed, and a novel high-speed image sensing
technique with adjustable frame rate based on an ordinary CCD was proposed. The principle of the image sensor was
analyzed. When the maximum frequency and channel bandwidth were fixed, a custom high speed camera was designed
by using the ordinary CCD under the control of the special driving circuit. The frame rate of the ordinary CCD has been
enhanced by reducing the number of pixels of every frame, therefore the ordinary of CCD can be used as the high frame
rate image sensor with small pixels. The multi-output high speed image sensor with small pixels by using this technique
can overcome the deficiencies of low resolution, low accuracy, and high price. The light intensity varying with time was
measured by using the image sensor. The frame rate was less than 1600frame/second, and the size of every frame and the
frame rate was adjustable. The correlation coefficient between the measurement result and the normal value was higher
than 0.95, and the relative error was lower than 0.52%. The feasibility of the high-speed image sensing technique was
proved by the experiments.
Research on CCD video signal processing based on correlated double sampling
X. Q. Wu,
L. Zhang,
X. J. Li,
et al.
Show abstract
In CCD detection to micro signals, it is a key technique that the output noise signals of CCD must be restrained or
attenuated, so that SNR (Signal-to-Noise Ratio) can be enhanced. This paper initially presents a brief description on the
characteristics of CCD output signals and usual processing schemes. And then, CCD output noise characteristics being
concerned, CDS (Correlated Double Sampling) is carefully analyzed. Lastly, on the basis of establishing CDS transfer
function and noise analysis model, the most proper CDS scheme is employed to test the performance of restraining KTC
noise and other low-frequency noises existed in CCD signals. And the results show that if only proper sample time is
chosen, 2δ -CDS circuit can not only remove KTC noise, but also restrain low-frequency noises and other white noises
in different degrees.
On the relationship between the illumination of bubble in water and the CCD gray pattern
Show abstract
Getting clear photographs of bubbles in water and extracting bubbles in the image of aerated water flows are the basis to
analyze the characteristics of water flows by image measurement. Because the bubbles in water are colorless, transparent
and deforming continuously, furthermore, they reflect and refract light at their boundaries. Up to now, almost all the
image processing of bubbles extraction in the images of aerated water flows have problems of miss-extraction or
deformity of bubbles which caused by un-uniformity of bubbles' boundary resulted from the un-balance illumination of
the image. In order to eliminate the noises in the background and identify the blurry boundaries, based on the systematic
analysis of the optical properties of bubbles in water, a set of formulas calculating the relationship between image gray
and bubble luminance are deduced in this paper which are applicable to different illumination settings and different CCD. A new method is developed to forecast CCD gray pattern based upon illumination variable and bubble shape, which was demonstrated by the experiments. The proposed method is expected to be used to design experimental scheme of image measurement, and can help to enhance the accuracy of image analysis.
Ultra-short electromagnetic pulse used for target detection
Show abstract
Two common approaches to generate ultra-short electromagnetic pulse are presented in this paper. One is that using a
high-speed avalanche transistor and another is that using a laser triggering photoconductive semiconductor switch
(PCSS). An ultra-short electromagnetic pulse with the rise time of 190 picosecond (ps), the pulse duration of 290 ps and
the amplitude of 2.2 kV, is radiated by an ultra-wide band (UWB) antenna. It is noted that the ultra-wide frequency
spectrum provided by the ultra-short electromagnetic pulses with duration of picosecond can be used to distinguish
different targets. The radiated pulse would transmit and be reflected by various targets within the detection range. By
analyzing the reflected signal, the corresponding reflection material can be discerned. The experiment is set up to
distinguish the iron metal and concrete wall respectively. The results show that such ultra-short pulse technology has an
excellent ability to distinguish objects.
The research on binocular vision based real-time object indication recognition method
Show abstract
In order to achieve a non-contact interactive operation in particular conditions such as high-temperature, high-voltage
conditions and space capsules, a real-time indicated object recognition method is proposed in this paper. It combines
eye-finger moving information to estimate the object position. Multi-camera is used to get images containing fingertips
and eyes, and binocular vision principle is utilized to estimate the 3D position of fingertips and eyes. According to
physiological characteristic, when people indicate objects, the line linking the center of his two eyes and fingertip will
pass the object point. So after capturing eyes and fingertips in video stream images with feature point extracting
algorithm, a model from 2D image coordination to object scene coordination which can be expressed as a projective
translation with multi-view restriction is presented. Using this model, 3D position of eyes and fingertips can be estimated
from 2D positions in images, and the line linking the center of a person's two eyes and his fingertip is obtained.
Intersecting this line and the plane which the object stand on it produces the object point which is the point indicated by
the person's finger. This method estimates the absolute position of the object, which means it needn't users to provide
any initial benchmark information. Finally, this method is tested by a practical indicated object recognition system with
error analysis of camera calibration and image processing result.
Simultaneous phase-shifting interferometry based on high-speed CCD
Show abstract
A new simultaneous phase-shifting measuring method based on Twyman-Green polarization phase- shifting technique is
presented. In the corresponding set-up, a 2-dimentional grating is applied. By the grating, 4 diffracted beams of (±1, ±1)
orders are formed for the same diffracting efficiency. Each is let to pass one of four polarizing plates respectively,
polarization directions of which differ in turn by 45°. So four interferograms with 90°phase-shifting interval are frozen
simultaneously by a high-speed CCD, which has short exposure of 1/10000 s. Moreover, by the use of 4-bucket
algorithm, a profile of the test surface is thus derived. Meantime, the system is deposited on a vibration-isolate flat, and
the structure of an ordinary piezoelectric transducer (PZT), with a time response above 1000 Hz at amplitude of &lgr;/2, is
used to simulate an epicenter, the frequency of which varying from 10 Hz to 200 Hz. In addition, the experimental
results reveal that the advanced system has a high testing precision and testing repeatability in the vibrational
environment whose amplitude- frequency product is less than 100 Wave-Hertz. Therefore, the proposed system has
enough endurance to the vibration during on-line optical testing.
Development of high frame rate CCD image remote acquisition system
Show abstract
This paper presents a high frame rate Charge Coupled Device (CCD) image acquisition system. The emphasis is the data
transmission and the data recording technology. The DALSA CCD camera head CA-D6 is utilized as the system imaging
unit. The CA-D6 output 35 pairs and input 2 pairs Low Voltage Differential Signals (LVDS) are analyzed. The switch
from LVDS to TTL signals is implemented. A pair of Agilent data transceivers HDMP-1022/HDMP-1024 is used to
encode/decode the digital image data. The system timing block is designed on Complicated Programmable Logic Device
(CPLD) technology. The internal program is explored on VHDL and schematic combination technology. The optic-fiber
transceiver HFCT-53D5 is applied to complete the data transmission to remote area. The VC++ environment application
software is developed based on data the acquisition card PCI-7300A. The imaging system can work at the frame rate of
up to 955fps. The transmission data rate can reach 1Gbps, and it can transmit the image data beyond 1.5 km area. The
system can be used in remote high-speed image acquisition field such as explosion analysis and radiation diagnosis.
Design and study of a new crepuscular imaging CCD
Show abstract
A novelty circumambulating transferred area array CCD (Charge Coupled Device) working method is proposed, and its
work feasibility is proved. The new CCD can change the existing CCD complex structure, enhance the translational
velocity and transfer efficiency, reduce the design production cost and the dark current through the best electronic
transfer frequency. To solve the limitations of big noise which contemporary exists on glimmer imaging plan in IICCD
(Image Intensified Charge Coupled Devices) and EBCCD(Electron Bombarded Charge Coupled Devices), short life and
other shortage, the weak optical image detect-ability is enhanced through changed the CCD periphery ancillary facilities
and micro-channel electron vase plate is designed. It is proved through changing dispersivity of the photocathode
electron emission once time and divergence of the speed, improved secondary electron launch randomness of imagining
intensifier, then reduced the system the dynamic survey noise, enhanced IICCD and the EBCCD survey limitation.
Synchronous control analysis of TDI-CCD imaging system
L. Zhang,
Y. X. Li,
X. W. Xu
Show abstract
The paper describes structure and principle of TDI-CCD image sensor. With help of the Modulated Transfer Function
(MTF), the negative effect on image quality is fully analyzed, which is caused by the mismatch between TDI-CCD line
scanning and velocity of image motion. After theory analysis and experiments, the results show that within the Nyquist
frequency, only the synchronous error is strictly controlled in the range of ±2%, and a continuous four-phase imaging
clock is employed, the effects of image motion is basically eliminated during process of imaging.
Review of current deveopments and trends of CMOS image sensors
Show abstract
With the development of VLSI, CMOS image sensor has developed increasingly. The history of CMOS image sensor
was introduced, on the basis of analyzing the principle of CCD and CMOS image sensor, the advantages of CMOS
image sensor was summarized. The current research status and commercial productions of different companies were
described in this paper, moreover, the technical specifications were presented. At last, the current applications and trends
of CMOS image sensor was focused.
Study CCD image motion for remote sensing detection
Show abstract
For remote sensing to measure upper atmospheric wind field by optical passive method on-load satellite, the emission
source is used of crepuscular aurora of OH 732.0nm. The time of exposure is need about 9sec by remodel Sagnac
interferometer, so there is a larger image motion on CCD and the measurement precision is limited. This paper has been
calculated the CCD image motion quantity based on remodel pushbroom model by Sagnac interferometer. The MTF
curve is demonstrated the image motion can be compensated. Then the techniques of TDICCD, the whole frame transfer,
swing mirror and photon memorizer to use compensate the image motion quantity.
Poster Session: Shock Wave and Hypersonic Physics
Planar nanosecond shock wave generation and propagation in poly vinyl alcohol investigated by CARS
Li Huang,
Yanqiang Yang,
Yinghui Wang,
et al.
Show abstract
Planar nanosecond shock waves were generated with ultrafast Gaussian laser pulses by using saturable dye-doped
polymer film as shock layer. Ultrafast spatially resolved Coherent Anti-Stokes Raman (CARS) spectra of shock
compression of a polycrystalline anthracene optical gauge were measured, and temporal profile and velocity of the shock
pulse were obtained. Detailed measurements showed the shock pressure, as indicated by the blueshift of an anthracene
vibrational transition, and the shock velocity, as indicated by the arrival time of shock wave at the anthracene gauge
layer, remains constant within better than 5% over the central region probed by CARS.
Poster Session: Photonics
Novel high-resolved spectroscopic studies of positive streamer corona
Yuri V. Shcherbakov
Show abstract
We have developed a fully self-consistent method of diagnostics of streamer discharge plasmas based on analysis of
absolute intensities of the second positive (SPS) and first negative (FNS) systems of molecular nitrogen. The theory of
the method combines a spectroscopic technique for calculation of temporal waveforms of the nitrogen absolute SPS and
FNS (0,0)-band emission and a self-consistent semi-analytical parametric axially symmetric 1.5D model of the
filamentary streamer head. The spectroscopic technique takes into account characterizations of all units of the measuring
spectro-optical channel, including spatiotemporal resolution and resolution in wavelength. The model of the streamer
head is characterized by some trial consistent allowable parametric on-axis profile of the electric field combined with the
electron and total space charge number density profiles fully self-consistent each with other and with the trial electric
field; all those expanded to 2D configuration via ellipse-like geodesic lines. The absolute values and the synchronous
ratio of the 1L spatially and time-resolved cross-correlated temporal waveforms of the SPS to FNS (0,0)-bands have
been used to reconstruct 2D structure of the streamer head. With a procedure fitting the directly computed output voltage
waveforms to the experimental ones, the peak values of the electric field and of the electron number density within
streamer head at mid-gap distances have been found to be 430÷500 Td and (2÷3)×1014 cm-3, respectively. The
corresponding absolute electric field became thus 70÷80 kV/cm at initial gas temperature within the repetitive streamer
region of 450 K. The results corroborate principal conclusions of the current-day streamer theory and numerical
modeling.
Property of a reflected Gaussian pulse beam
Show abstract
It is theoretically discussed the reflective property of a Gaussian pulse on the planar dielectric interface. When the
decoupling and full-interference approximations are considered, the axes of reflected pulse beam undergoes a lateral shift
from the position predicted by geometrical optics. At the same time, the reflected pulse beam still emerge the time delay
comparing to the incident pulse beam. The reflected profile is different from the incident pulse beam. Both spatial
distribution and temporal distribution of the reflected pulse beam come out the aberrance.
Comparison of Fourier-transform analysis with wavelet-transform analysis in terahertz time-domain spectroscopy
Show abstract
In this paper, we applied wavelet-transform to analysis the water vapor absorption spectroscopy in terahertz range, and
compared with conventional Fourier-transform analysis in terahertz time-domain spectroscopy. The extracted absorption
lines are in excellent agreement with the results of using Fourier-transform analysis. The results show that
wavelet-transform analysis of the absorption spectrum delivers accurate absorption lines in THz range. Because the
results are shown in a time-frequency domain, it gives a more intuitive image on when the absorption happens at which
frequency. Combining wavelet-transform technique with THz-TDS, we hope there births a new spectroscopy: the
wavelet-transform terahertz time-domain spectroscopy.
Design of hybrid diffractive/refractive optical system by the method of P-W-C
Show abstract
The structure parameter of hybrid diffractive/refractive optical system has been solved by the method of P-W-C. The
primary aberration equation for diffractive system has been deduced. Combination of 3 pieces lenses, the diffractive/
refractive hybrid optical system was designed: No.1 and No.3 are common glasses; No.2 is binary optical lenses (BOL).
The results show: The Longitudinal Aberration is good in 0.6 and 0.8~0.9 apertures for the lenses. When frequency is
30lp/mm, the modulation transfer function (MTF) is close to diffractive limit in 0.5 field angle; the modulation transfer
function (MTF) is close to 0.7 in edge field. The design method can be used for diffractive/ refractive hybrid optical
system.
Research and fabrication of integrated bio-sensor for blood analysis based on uTAS
Show abstract
For simultaneously detecting multi-parameters of blood in the clinical diagnosis, the analysis apparatus should be smaller
in size, more reliable and sensitive. So a kind of integrated bio-sensor for blood analysis based on Micro Total Analysis
System (μTAS) is presented. It provides modern bio-sensor prospect with a novel technology.
A multi-parameters of blood analysis integration sensor is μTAS bio-sensor based on 4 groups of interdigital array (IDA)microelectrodes. The IDA microelectrodes are fabricated on glass substrates by photography, film deposition and
other microfabrication techniques. Thin-film gold microelectrode with a thickness of 250nm is deposited on a chromium-adhesion
layer. The finger microelectrode width and space are both 10μm. The work space is 2×2cm2. The concentration
of Blood sugar, Total Cholesterol, Acetone body and Lactic acid is measured by detecting steady-state limiting
currents in IDA microelectrodes modified with enzymes on the "generate-collect" mode. Blood distribution structure is
designed and fabricated, to distribute blood and isolate reaction areas. By contrasting two kinds of process flow based on
lift-off and etching, etching is adopted to preparation method of microelectrode.
A multi-channel apparatus for current measurement is accompleted. The system characteristics of the bio-sensor are
tested. The curve of the apparatus time to current response is achieved by testing on real-time. The relationships between
parameter concentration and current are analyzed in detail. The experimental data indicates: current measurement
dimension 0~40μA, certainty of measurement 0.1μA, the performances of the bio-sensor meets design requirement.
Beam-smoothing investigation on Heaven I
Yi-huai Xiang,
Zhi-xing Gao,
Xiao-hui Tong,
et al.
Show abstract
Directly driven targets for inertial confinement fusion (ICF) require laser beams with extremely smooth irradiance
profiles to prevent hydrodynamic instabilities that destroy the spherical symmetry of the target during implosion. Such
instabilities can break up and mix together the target's wall and fuel material, preventing it from reaching the density and
temperature required for fusion ignition.1,2 Measurements in the equation of state (EOS) experiments require laser beams
with flat-roofed profiles to generate uniform shockwave3. Some method for beam smooth, is thus needed. A technique
called echelon-free induced spatial incoherence (EFISI) is proposed for producing smooth target beam profiles with large
KrF lasers. The idea is basically an image projection technique that projects the desired time-averaged spatial profile
onto the target via the laser system, using partially coherent broadband lighe. Utilize the technique, we developing beam-
smoothing investigation on "Heaven I". At China Institute of Atomic Energy , a new angular multiplexing providing with
beam-smoothing function has been developed, the total energy is 158J, the stability of energy is 4%, the pulse duration is
25ns, the effective diameter of focusing spot is 400um, and the ununiformity is about 1.6%, the power density on the
target is about 3.7×1012W/cm2. At present, the system have provided steady and smooth laser irradiation for EOS
experiments.
Research on light signals extraordinary compressed using periodic structure modulated method in photorefractive materials
Show abstract
During some high processing, such as high-speed photography and so on, the encode pulse or driving signal must be
compressed with full optics system. According to the light speed can be slowed down in a photorefractive crystal bar in
which written volume-index grating by two laser beam, so as to the light signal may be transmitted in slow speed under 1/
7 of light speed in vacuum. Because the genesis of the phenomenon is the inner index periodic structure, so the out put
signal compressed may be realized through erasing the periodic structure in the opposite direction of signal beam using
another laser beam when the signal light transmitting the crystal bar. However, every finite signal stream can be further
compressed by the same way again. Different erasing method would get many kinds of out put signal to adapt to various
design.
Measurements of fibers' thermal-optic coefficient based on optical fiber Bragg grating sensor
Jing Ye,
Baojin Peng,
Jianwen Fang,
et al.
Show abstract
Optic fibers are applied in the field of high speed photography more and more, for its good properties. At present, various new-style fibers come out, and these new-style optic fibers' core material are not based on pure quartz traditionally. To know the new-style fibers' properties quantitatively, thermal-optic coefficient is indispensable to get. Therefore this article describes a new way to measure fibers' thermal-optic coefficient based on optical fiber Bragg grating(FBG) sensor. With a temperature referrence grating and a measuremental grating, experimental system is developed, combined with the characteristics of fiber Bragg grating. Experimental setup and measurement principle are discussed. The result of experiment proves that the system can solve the existent cross sensitive problem which caused by temperature and the strain effectively. The fibers' thermal-optic coefficient are measured successfully, within ±1%.
Analysis on strain and temperature sensing characteristic of sampled fiber grating
Show abstract
Sampled fiber Bragg grating(SFBG) has caused extensive research interest due to its special filtering characteristic, strict
wavelength interval, compact structure, easy integration and low cost etc. Based on coupling-mode theory, the reflective
spectrum of sampled fiber Bragg grating was analyzed using transmission matrix method. Strain and temperature sensing
characteristics of sampled fiber Bragg grating were discussed in the paper. Wavelength shift and transmission intensity
vary linearly with strain and temperature. The change of strain and temperature can be determined simultaneously by a
single sampled fiber grating. In the experiment, the strain and temperature of sampled fiber Bragg grating change
simultaneously, the photoelastic coefficients of sampled fiber Bragg grating were P11=0.121, P12=0.27. The Poisson ratio
of optical fiber core stuff was 0.17, the thermal expansion coefficient was 5.5×10-7/°C, and the calorescence coefficient
of optical fiber was 8.3×10-6/°C. We can get that A, B, C and D were separately -0.00055nm/ε, 0.013nm/°C, -
0.00033/ε, -0.00011/°C by calculating. Strain measurement ranged from 0 με to 2500με. Temperature measurement ranged from 0°C to 300°C.
Continuous-wave diode-pumped Yb3+: LYSO tunable laser
Show abstract
A new alloyed crystal, Yb:LYSO, has been grown by the Czochralski method in our institute for the first time, and its
effective diode-pumped cw tunable laser action was demonstrated. The alloyed crystal retains excellent laser properties
of LSO with reduced growth cost, as well as the favorable growth properties of YSO. With a 5-at.% Yb:LYSO sample,
we achieved 2.84 W output power at 1085 nm and a slope efficiency of 63.5%. And its laser wavelength could be tuned
over a range broader than 80nm, from 1030nm to 1111 nm. This is the broadest tunable range achieved for Yb:LYSO
laser, as far as we know.
Fiber micro-vibration readout sensor based on MOEMS
Show abstract
To measure the vibration of micro-structure, a scheme of sensor based on MOEMS (Micro-Optic-Electro-Mechanical
System) with fiber-optic readout was proposed, and its mathematical model was deduced. Single-fiber readout structure
and a micro-structure fixed in the front of the sensor were used. The micro-structure vibrated as the measured object
moved, and its vibration caused the change of light intensity. The sensor detected vibration displacement by receiving
the light intensity. As a result of single-fiber structure and parameters optimization of micro-structure, compared with
other fiber readout structures, this system has the advantages of high sensitivity and miniaturization which is easier to
match with fiber system because of single-fiber structure and parameters optimization of micro-structure. The response
behaviors of the system to the piezoelectric ceramics excitation were studied through the experiments. And it could
detect the vibration displacement of 0.18nm.
Research on the active recovery technology of optical fiber radiation effect
Yanling Han,
Wen Xiao,
Xiaosu Yi,
et al.
Show abstract
The light transmission characterizes of the optical fiber was changed when it has been exposed in the radiation
environment due to the radiation induced defects and the formation of color centers. On the other hand, the damage of
crystal lattice was recombined simultaneously due to the effect of light or thermal when the color centers were forming.
Moreover the effect assisted by light is commonly called photobleaching which is directly proportional to the light power
and inversely proportional to the light wavelength. Based on the effect, the radiation induced loss can be reduced by
emitting high-power light to fiber. In this paper, the active recovery effect has been put forward to reinforce the fibers'
radiation resistance using two sources after the detailed analysis of the fiber radiant effect and color center model. In
addition, the application importance of the methods was also discussed.
Research on dual phase-shifted fiber gratings sense and signal disposal
Ke-Jia Wang,
Qi Wang,
Yi Wang
Show abstract
The paper proposes a kind of scheme that uses dual way to construct a differential type fiber gratings sensor and signal
control method. The sensor utilizes cantilever structure to little answer sense and possesses better optical frequency
heterodyne regulated performance via stepper motor modulation. The dual differential type phase-shifted fiber gratings
can be convenient regulation and scans frequency to proceed to heterodyne laser communication. It is proved that the
scheme possesses many excellent characteristics such as upper sensitivity, powerful anti-jamming capacity. The scheme
enters into a new domain of laser atmospheric communication system signal demodulation.
The coherence properties of supercontinuum spectra generated in photonic crystal fiber
Show abstract
Temporal coherence property of supercontinuum (SC) generated in a polarization-maintaining photonic crystal fiber
(PM-PCF) pumped by Ti:sapphire fs laser was experimentally studied by using a modified Michelson interferometer.
The coherence length of supercontinuum light was measured to characterize the temporal coherence property. The
coherence lengths of supercontinuum and pump laser were measured to be 6.5 μm and 59.14 μm, respectively. The
shortened coherence length of supercontinuum output from the PM-PCF was due to the broadened spectrum. Moreover,
the interferogram evolution versus the supercontinuum spectra was also investigated. It was indicated that the flatter the
supercontinuum was, the better the interferogram was.
Simultaneous strain and temperature measurement system with fiber Bragg grating
Show abstract
Simultaneous strain and temperature measurement system with fiber Bragg grating was presented in this paper. The light
from broadband source (BBS) was coupled into sensing probe through 3dB coupler1. Reflective light of two FBGs was
split through coupler2 and went into chirped gratings with different pass-band. Demodulation method adopted chirped
grating and long period grating edge linear filtering technology. It can send each reflected spectrum to different edge
filter. It makes every FBG's reflective spectrum was demodulate. The central reflected wavelength of two FBGs was
1546.15nm and 1554.17nm respectively. Through simulation experiment, we can get that (formula available in manuscript). Strain measurement ranged from 0 to 2000 με. Temperature measurement ranged from 0 to 200°C.
Research on character of fiber overcoupled devices
Show abstract
Utilizing the fused-taper technology, a fiber coupler with sensitive to wavelength and strain is obtained. This type
coupler is fabricated after Nth coupling period. They are usually called overcoupled devices, N is the number of coupling
period, N>>1. The relation between wavelength and coupling ratio of the coupler is analyzed. The maximum sensitive
wavelength can be control by the fused-taper technology. When a Bragg wavelength of the fiber Bragg grating (FBG) is
agreed with the maximum sensitive wavelength of the coupler, the shift of the Bragg wavelength is can be detected. In
this paper we demodulate one FBG which Bragg wavelength is at 1564.69 with the coupler. So the coupler with sensitive
to wavelength can be used to demodulate the FBG. And the sensitive to strain of the coupler is also analyzed. The
experimental data is present as the theory value, sinusoidal curve. So the coupler can also be used to detect the strain and
the temperature with the packaging of the thermal sensitive. The overcoupled couplers have a potential application to the
sensing system.
Application research on optical grating in fiber gyroscope
Show abstract
The paper proposes a scheme that utilizes phase-shifted fiber gratings technology to proceed to annual fiber gyroscope
detection. As sharpness of resonance and polarization influences, the fineness of annual fiber gyroscope detective
sensitivity gets limit. The solution method is to use the phase-shifted fiber grating to compress breathe of frequency. It
can enhance sharpness of resonance, improve detective sensitivity and weaken parasitic interference influence. It is
proved that phase-shifted fiber gratings play an important role to annular fiber gyroscope detective sensitivity validity
and polarization weak influence. The scheme breaks a new path that enhances annual fiber gyroscope performance and
predigests detective system.
High-precision optical fiber liquid-level sensor based on a sensitive and extrinsic Fabry-Perot interferometric cavity
Tao Lü,
Desen Liu
Show abstract
A novel intensity-based optical fiber liquid-level sensor based on a sensitive and extrinsic Fabry-Perot (F-P)
interferometric cavity is described in this paper. The novel sensing schemes combines the advantages of both
interferometry sensors and intensity-based sensors. The sensor operates on a single fiber F-P interferometric cavity with a
DFB-LD light source. The elastic silicon slice replaces conventional reflected multimode optical fiber in extrinsic optical
fiber F-P sensor as sensing element. Several steps have been taken to eliminate or restrain temperature effect influencing
on the sensing system. Experimental results indicate a precision as high as 1.2mm of a full scale 3.5m (water) is obtained.
The optimized sensor can be used in explosive and flammable environment to measure liquid-level continuously and
accurately.
High power LD-end-pumped Nd:YVO4 laser as a pump source for Raman fiber laser
Show abstract
A LD-single-end-pumped Nd:YVO4 CW all-solid-state laser with maximum output power 12.5W at 1064nm was
designed to pump the cascaded phosphosilicate fiber Raman laser. The Nd:YVO4 laser is lower in cost than Yb-doped
cladding fiber laser which is usually used as a pump for Raman fiber laser. However, it is inefficient to couple pump
beam into single mode fiber (SMF). The coupling efficiency from pump beam to SMF is largely affected by the beam
quality. Thus, a high coupling efficiency requires maintaining laser's operation in the TEM00 mode while scaling the
power. The beam quality and maximum output power of the Nd:YVO4 laser is restricted by the thermal lens and fracture
within the gain medium under high pump intensity conditions. The thermal effects was decreased by using a 3×3×
10mm3 Nd:YVO4 crystal with a low neodymium-doped concentration (0.3at%). Furthermore, a plane-plane resonant
cavity with large mode volume and a large pump size was also used to reduce the effects. The Nd:YVO4 laser with
maximum output power 12.5W and M2<1.2 was obtained. More power than 4W was injected into cascaded Raman
cavity at the maximum pump power and about 1W coherent second-order Stokes radiation at 1484nm was achieved.
Hi-bi-nlcfbg and hi-bi-ufbg used to compensate all-orders pmd
Xianjie Feng,
Cuimei Li,
Lan Chen
Show abstract
The first- and second- and third-order polarization mode dispersion has become a critical issue for high-data-rate optical systems. This paper advance a two-stages PMD compensator, which are made of a long length of Hi-Bi-NLCFBG(high-birefringence nonlinearly chirped fiber Bragg gratings) and a short length of Hi-Bi-UFBG(high-birefringence uniform fiber Bragg gratings). The first stage adopts a Hi-Bi-NLCFBG[1], which been used compensated the first- and second- orders PMD, and the second-stage adopts a Hi-Bi-UFBG, which used for third-order PMD compensation, respectively. Based on the numerical simulations, the spectrum characteristics and time delay of Hi-Bi-NLCFBG is investigated, then, we put forward that the amount of compensated PMD is proportion to length of Hi-Bi-NLCFBG, double-mode refraction index difference of highly birefringence fiber for the first time. Also, we modify a formula aiming to former literature; It is suggested that the value of first-chirped coefficient of Hi-Bi-NLCFBG must be suitable, or else, the effect of compensated PMD is bad. Subsequently, the differential group delay (DGD) of NLCFBG of normal polarization-mode of the single-polarization fiber is analyzed by means of numerical simulation, and we also analyzed the PMD of NLCFBG UV-writing leak-mode of the SP-SMF (Single Polarization Single Mode Fiber) In order to compensated the third-order PMD, we investigate the out-of-band time-delay of UFBG on the SP-SMF at the end of this paper.
Optical forces on a microscopic object of dual-beam optical fibers
Show abstract
We studied the optical forces acting on a microscopic object generated by the laser beams from lensed optical fiber ends
to research the parametric influence on the optical trapping. From these investigations, we verified that there was only
one stable point of equilibrium located below the beam-crossing point, and revealed that the radius of a hemispherical
microlens of an optical fiber end, the horizontal distance between each optical fiber end and the particle size are
important parameters for strong three-dimensional trapping without physical contact.
Study on ameliorating the FEC coding techniques in current high-rate optical transmission systems
Show abstract
In this paper, the three ameliorated new coding schemes of the Super-FEC (Forward Error Correction) concatenatedcodes
(namely, the inner-outer concatenated-code, the parallel concatenated-code and the successive concatenated-code
with interleaving) are proposed after the development trend of high-rate optical transmission systems and the defects of
the FEC codes in the current optical transmission systems have been analyzed. The system simulation of the inner-outer
concatenated-codes is implemented and the schemes of encoding/decoding the parallel concatenated-codes are proposed.
Furthermore, the two successive concatenated-codes with interleaving of the RS(255,239)+RS(255,239) code and the
RS(255,239)+RS(255,223) code are simulated, and the analyses for the simulation results show that the two successive
concatenated-codes with interleaving, compared with the classic RS (255,239) code and other codes, are a superior code
type with the advantages of the better correction error, moderate redundancy and easy realization. And their net coding
gains (NCG) are respectively 1.5dB, 2.5dB more than that of the classic RS(255,239) code at the BER (Bit Error Rate) of
10-12. At last, based on the ITU-T G.709, the frame format of the new concatenated-code on applying in high-rate optical
transmission systems is proposed and designed, this lays a firm foundation in order to design its hardware in future and
pioneers a direction in its physical application.
2D and 3D multiple optical tweezers
Show abstract
In this article, we present the way how to generate an interference field created by two or three beams having their
optical axes in one plane, therefore got the so called 2D interferometric optical tweezers. Firstly, we analyzed the
arrangement where two co-propagating laser beams intersect at an angle and interfere there, the fringes so produced
behave as an array of two-dimension multiple optical tweezers. Then we quantified the property of these traps by
analyzing the forces exerted on the polystyrene beads. The last, we added the third counter-propagating beam that
balanced the radiation pressure of the other two beams but did not interfere with them. Through this method, we can
confine polystyrene beads at a given distance between the two surfaces of the sample cell. This also can be called the 3D
traps. We also theoretically compared the lateral optical trap forces between 2D and 3D tweezers.
Analysis of amplifier spontaneous emission noise in Raman fiber amplifiers
Zehua Hong,
Zhihui Gao,
Aihua Yu,
et al.
Show abstract
In this paper temperature dependent models have been proposed that accurately describe amplified spontaneous emission
in discrete and distributed Raman amplifiers. Using those models we analyzed a few main factors which influence the
amplified spontaneous emission (ASE) noise. Rayleigh scattering that can enlarge the power of ASE noise is taken into
consideration. So we have got a more accurate result.
Influence of two-photon absorption and optical excitation size on the THz radiation via optical rectification
Liying Lang,
Xiannong Wang,
Xueguang Wang,
et al.
Show abstract
Although the ZnTe crystal used the generation of THz radiation has a favorable phase matching properties at 820nm, it
has strong third-order nonlinearity, such as two-photon absorption effect. And we found experimentally that, the effect of
two-photon absorption in ZnTe on the THz radiation was not neglect. In addition, due to optical rectification and
diffraction effect, the generated efficiency of THz radiation is also related to the optical excitation size in the emitter. In
this paper, by taking into account optical rectification, diffraction and two-photon absorption effects, the theoretical
model is established to describe the emitting field intensity of THz radiation. There is excellent agreement between the
theoretical results and the experimental data. The good agreement demonstrates that there is a trade-off between these
three effects for THz radiation.
Design and optimization of a high-power L-band ASE fiber source
Show abstract
Two kinds of configurations of L-band amplified spontaneous emission (ASE) source with two-stage EDF and dual
forward pumps are suggested for generating a high power L-band ASE spectrum. The characteristics are theoretically
compared in terms of the output power, pumping conversion efficiency, bandwidth, and mean wavelength stability for
these two configurations. The EDF length and pump power allotment are also optimized. An L-band ASE source of
76mW output power with about 36.2% pumping conversion efficiency are experimentally obtained.
Static modeling for membrane deformable mirror used in high-power laser
Peng Wu,
Haiqing Chen,
Jie Li,
et al.
Show abstract
The technology of membrane deformable mirror (DMs) that has the potential to achieve comprehensive wavefront
compensation and control in high power laser has been developed rapidly in recent years. Experimental results reveal
that strong nonlinearity is induced to the deformation of DMs with respect to the square of input voltage when operating
voltage is more than 120V. The nonlinear response and strong coupling effect of control channel in DMs make it
difficult to obtain the desired mirror surface shapes. A test bed is built up to measure the deformation of DMs driven by
specified voltages. An efficient nonlinear model of deformation with respect to input voltages is presented using a back
propagation neural network (BPNN). Deformation due to arbitrary actuator voltages applied to actuators to correct
wavefront aberration can be calculated directly with a higher precision using the BPNN model proposed. The residual
relative error of the proposed model shows the improvement of accuracy of an order about 5 as compared to that of
linear model, and with no significant increase of time consumption. A preliminary open-loop control experiment of laser
wavefront compensation is performed to exam the validity of applying the proposed BPNN model in laser wavefront
compensation application.
Application of Monte Carlo simulation in airborne modulated lidar for bathymetric detection
Show abstract
The sensitivity of lidar (light detection and ranging) and the contrast of immersed targets are strongly reduced by the
volume backscattering clutter. To overcome this shortcoming it has been proposed to use a microwave modulation in
association with an optical carrier at 532nm, which is called modulated lidar. This paper develops a Monte Carlo
simulation for application of modulated pulse lidar (light detection and ranging) in bathymetric measurements. First,
modulated light pulse propagation in ocean water is simulated by a Monte Carlo model. Second, the echo signal is
processed by advanced mathematical tools like cross-correlation and numerical filtering. The simulation results reveal
the capability of the modulation approach in suppressing the water backscattering and enhancing the target contrast for
the bathymetric field. Furthermore, more simulation experiments are performed with various ocean depth to study the
detection performance in different environment. Details of this simulation model, in addition to the simulation results are
presented.
Optical measurement methods of Dragon-I accelerator
Show abstract
Optical methods have many advantages in the beam measurement of particle accelerators. We use transition radiation
and Cerenkov Radiation to measure the beam of Dragon-I linear induction accelerator. Beam profile, beam emittance,
beam energy and energy dispersion are measured with the help of these radiations.
Annular photonic crystal defect mode for operation of single-mode laser
Show abstract
In analogy to the impurity levels of semiconductors, optical cavities are created if irregular regions are introduced into
the perfect photonic crystals. Photonic crystal single defect cavity is expected to obtain nearly thresholdless laser because
it can create wavelength-scale small resonant mode with high-quality factors and high spontaneous emission coupling. In
this paper, we have studied a new type of defect called annular microcavity created by drilling a circular hole in a usual
defect cylinder in two-dimensional triangular photonic crystal by using the supercell method. The hole within the rod
greatly modifies the defect modes by controlling filling fraction of dielectric material from the inner of the defect and
lowering symmetry of the defect. It is found that the annular defect provides extra two more variables due to the hole
(radius and refractive index) that can be utilized to alter the properties of the defect. And this opens up a new method to
achieve and tune acceptor-mode cavity. Moving the hole can split the degenerate modes. The departure displacement
determines the splitting space and the departure angle determines symmetry of distributions of electric fields. These
results exhibit more advantages over the conventional defects and may be utilized to single-mode operation of
microcavity laser.
Hollow-core optical fiber for terahertz wave propagation
Bing Zhang,
Rong-jin Yu
Show abstract
The possibility of using a hollow-core Bragg fiber with cobweb-structured cladding to obtain low-loss transmission in
terahertz (THz) frequency range is proposed and analyzed. Leaky losses of the fiber are analyzed as a function of the
structure parameters for hollow-core Bragg fiber with cobweb cladding, such as number of alternating layers, core radius
and width of air layer by an asymptotic matrix formalism. An estimate of the transmission losses of such fibers in longwavelength
and short-wavelength range of THz wave is given. The results show that the transmission losses of the
hollow-core Bragg fiber with cobweb cladding are far less than those of other fibers for THz wave reported so far in the
literature.
The research on the photo-electronic integrated acceleration seismic detecting technology
Show abstract
For high resolution application in seismic detection, the geophone should be smaller in size, more reliable and sensitive.
So a kind of photo-electronic integrated acceleration seismic detecting technology, which is novel and precise based on
waveguide M-Z interference, is presented. The principle of the photo-electronic integrated acceleration seismic geophone
is introduced in this paper. The seismometer is composed of a waveguide M-Z interferometer, a sensing element, a
modulation LD and signal processing system. The silicon crystal is adopted as the substrate. The core of the photoelectronic
integrated acceleration is the silicon harmonic oscillator, which is supported by four silicon beams and
integrated on the signal beam of the M-Z interferometer . The harmonic oscillator translates the acceleration information
of the external vibrational signal into phase variation of optical signal in the sensing arm, which is converted into optical
signal by M-Z interferometer, then PIN converts the optical signal into electric signal to process by the signal processing.
The experimental curve of seismometer frequency response is achieved.
ECLD at 1.5um with acetylene saturated-absorption frequency stabilization
Show abstract
The frequency-stabilized laser in 1.5μm region is vital important for high capacity Dense Wavelength Division
Multiplexing (DWDM).The acetylene (C2H2) saturated absorption frequency stabilization can be used to stabilize the
frequency of laser in 1.5μm region. A fiber grating external cavity semiconductor laser diode(ECLD) was designed
according to the method of frequency stabilization, which used step motor to strain the fiber grating to tune the
wavelength, and modulated the power of light by modulating the injecting current. The effect of frequency stabilization
was authenticated by experiment.
Investigation of solid-state lasers aberration compensation using an intra-cavity adaptive optic mirror
Zhengang Yang,
Haiqing Chen,
Jiafeng Chen,
et al.
Show abstract
Thermal induced distortion in the gain element is the main obstacle to be overcome in the scaling of solid-state lasers to
very high output powers. The resultant distorted thermal lens cannot be compensated for by cavity design alone. The
investigation of the possibility to influence on the output beam parameters of a solid-state laser by methods of intracavity
adaptive optics was carried out. An adaptive optic mirror has been used intra-cavity to control the output power of
a solid-state laser. Power and beam profiles optimization are demonstrated by closed loop automatic optimization of the
deformable mirror.
Weighted least squares phase unwrapping based on the wavelet transform
Jiafeng Chen,
Haiqin Chen,
Zhengang Yang,
et al.
Show abstract
The weighted least squares phase unwrapping algorithm is a robust and accurate method to solve phase unwrapping
problem. This method usually leads to a large sparse linear equation system. Gauss-Seidel relaxation iterative method is
usually used to solve this large linear equation. However, this method is not practical due to its extremely slow
convergence. The multigrid method is an efficient algorithm to improve convergence rate. However, this method needs
an additional weight restriction operator which is very complicated. For this reason, the multiresolution analysis method
based on the wavelet transform is proposed. By applying the wavelet transform, the original system is decomposed into
its coarse and fine resolution levels and an equivalent equation system with better convergence condition can be
obtained. Fast convergence in separate coarse resolution levels speeds up the overall system convergence rate. The
simulated experiment shows that the proposed method converges faster and provides better result than the multigrid
method.
Experimental study on period doubling of multiple quantum well Fabry-Perot laser
Show abstract
We experimentally study the period doubling phenomenon of gain-switched multiple quantum well Fabry-Perot laser
diodes with/without external optical injection. The relations between resonance frequency and modulation frequency are
analyzed detailedly when period doubling occurs. The obtained research results indicate that external optical injection
may be an effective technique to suppress or enhance period doubling of a gain switched laser diode with injection
optical power. Experiments show that the period doubling would appear in a broader frequency range with external
optical injection, and indicate that period doubling occurs over a wide range of modulation frequency in laser diode as
the injection power increases. Moreover, we have studied in detail that period doubling easily occurs when bias current is
located between 1.1Ith and 1.3Ith, and modulation current is set between 0.5Idc and 2.5Idc.
Numerical analysis on the cooling characteristics of finite Nd: GGG slab in a solid state heat capacity laser
Liqun Hou,
Jifeng Zu,
Yue Dong,
et al.
Show abstract
In this paper, based on the fundamental theories of heat transfer, we researched the cooling characteristics of a finite Nd:
GGG slab working in HCL mode. The 3D thermal and stress fields in the slab are simulated by the ANSYS firstly, then
distribution rules of temperature and stress are outlined, and the influences of coolant temperature and convective heat
transfer coefficient on the cooling effects are also discussed. At last, a cooling method with increasing continuously flow
rate coolant in normal temperature is proposed. As a result, the maximum cooling stress could be depressed down about
ten percents and cooling procedure is also shortened. It can be suitable to some special SSHCLs' applications that have
higher demand for cooling time.
CW and tunable laser operation of Yb3+ doped Gd0.2Y0.75(BO3)4
Show abstract
As self-frequency-doubled (SFD) lasers are potentially more compact and less costly, the novel high efficient SFD lasers
attract great interest. Here we report the spectroscopic properties under room temperature of a new self-frequency-double
Yb3+ doped Gd0.2Y0.75(BO3)4 (Yb:GdYAB) single crystal grown in Shandong University. Both foundation and
self-double-frequency continuous-wave laser were operated with a high-power diode. A foundation laser slope
efficiency of 82% with respect to the absorbed 975 nm pump power of 2.62 W was obtained. The center wavelength at
1040nm was generated and the laser wavelength could be tuned from 1020 to 1064 nm. And thus, the broadly emission
spectra was advantageous for the production of short-pulse diode-pumped solid state lasers. Self-double-frequency green
light was also obtained under pump power of only 274mW with a flat-concave cavity. The maximal output power was
330mW when pumped power was 2.62 W. A diode-to-green optical conversion efficient of 12.6% was achieved. The
results demonstrated that the Yb:GdYAB crystals are potential candidates for efficient microchip both 1 μm and visible
laser media.
Artificial retina model for the retinally blind based on wavelet transform
Show abstract
Artificial retina is aimed for the stimulation of remained retinal neurons in the patients with degenerated photoreceptors.
Microelectrode arrays have been developed for this as a part of stimulator. Design such microelectrode arrays first
requires a suitable mathematical method for human retinal information processing. In this paper, a flexible and adjustable
human visual information extracting model is presented, which is based on the wavelet transform. With the flexible of
wavelet transform to image information processing and the consistent to human visual information extracting, wavelet
transform theory is applied to the artificial retina model for the retinally blind. The response of the model to synthetic
image is shown. The simulated experiment demonstrates that the model behaves in a manner qualitatively similar to
biological retinas and thus may serve as a basis for the development of an artificial retina.
Accurate non-effective pixel detection and replacement based on multi-temperature matching
Show abstract
The number and distribution of non-effective pixels is an important quality figure that defines a given infrared focal
panel array (IRFPA). An accurate non-effective pixel detection algorithm is present in this paper. Through theoretical
analysis of IRFPA responsivity suitable definition of non-effective pixel is given. Based on this definition an adaptive
threshold is proposed to discriminate various non-effective pixels and normal pixels. Meanwhile, multi-temperature
matching approach helps us to pick out the hided non-effective pixel under a certain temperature range. Finally,
neighboring pixel interpolation is performed to substitute non-effective pixels according to spatial correlation. The
benefit of this method is reducing misjudgment of non-effective pixels, which will degrade infrared image quality. This
approach for detecting and replacing non-effective pixels is successfully applied to a set of frames obtained from an
IRFPA imaging. Results show that the detection and replacement accuracy of non-effective pixels is greatly improved by
this approach. Furthermore, the proposed algorithm is adaptable to a variety of non-effective pixel types.
A novel imaging method for photonic crystal fiber fusion splicer
Show abstract
Because the structure of Photonic Crystal Fiber (PCF) is very complex, and it is very difficult that traditional fiber fusion
splice obtains optical axial information of PCF. Therefore, we must search for a bran-new optical imaging method to get
section information of Photonic Crystal Fiber. Based on complex trait of PCF, a novel high-precision optics imaging
system is presented in this article. The system uses a thinned electron-bombarded CCD (EBCCD) which is a kind of
image sensor as imaging element, the thinned electron-bombarded CCD can offer low light level performance superior to
conventional image intensifier coupled CCD approaches, this high-performance device can provide high contrast high
resolution in low light level surveillance imaging; in order to realize precision focusing of image, we use a ultra-highprecision
pace motor to adjust position of imaging lens. In this way, we can obtain legible section information of PCF.
We may realize further concrete analysis for section information of PCF by digital image processing technology. Using
this section information may distinguish different sorts of PCF, compute some parameters such as the size of PCF
ventage, cladding structure of PCF and so on, and provide necessary analysis data for PCF fixation, adjustment,
regulation, fusion and cutting system.
Effects of annealing on the photoluminescence of terbium-doped zinc oxide nanocrystalline
Guo-li Song,
You-Tong Yang
Show abstract
Terbium-doped zinc oxide nanocrystalline are successfully prepared by Sol-Gel process at various annealing temperature
from 400°C to 800°C. Photoluminescence spectrum (PL), Photoluminescence spectrum excitation(PLE) and X-ray
diffraction pattern(XRD) of nanocrystalline ZnO:Tb3+ with excitation wavelength 368nm are measured at room
temperature. XRD pattern indicates that nanocrystalline ZnO:Tb3+ has a hexagonal wurtzite structure and polycrystalline.
The mean grain size of nanocrystalline ZnO:Tb3+ was 8nm~12nm calculated by Debye-Scherrer formula. Emission
from 5D4→7F6 (485nm), 5D4→7F5 (544nm), 5D4→7F4 (584nm) and 5D4→7F3 (620nm) of Tb3+ ions, and wide
visible band of ZnO were observed. Relationship between Photoluminescence intensity of the peaks of nanocrystalline
ZnO:Tb3+ and annealing temperature were given, it was found that the optimal dopant concentration and annealing
temperature was 4at% and 600°C. The luminescence process of Tb3+-doped zinc oxide nanocrystalline has investigated
by using PL, PLE and XRD. Photoluminescence mechanism suggests that there is energy transfer between ZnO
nanocrystalline hosts and the doped Tb3+ centers.
Range finding with chaotic laser train generated from laser diode with optical feedback
Show abstract
Range finding with continuous-wave chaotic laser train generated from laser diode with optical feedback is investigated
theoretically. Chaotic laser is split into probe beam flighting to target and reference beam, and then, the distance of target
can be calculated from the flight time obtained by correlating the time-delayed probe beam with the reference one.
Effects of noise and waveform error on correlation performances for different chaotic states are investigated to study the
system tolerance of environmental noise. Simultaneously, the effects of chaotic state characterized by the largest
Lyapunov exponent and correlation dimension on correlation performances are demonstrated theoretically to select
satisfying chaotic laser used as probe light. Simulated results indicate that ideal chaotic laser train should have high
dimension and have smooth spectrum with broad bandwidth for ranging with high resolution. For the simulated system,
ranging resolution within 1.5cm range independent of target location can be achieved using the chaotic lasers generated
in middle of the chaos-generated regime of feedback level.
Photochromic diarylethenes for two-wavelength optical recording
Show abstract
We have carried out successfully two-wavelength photon-mode optical storage using photochromic diarylethene
materials, 1,2-bis(2-methyl-5-(2-(1,3-dioxolane))-thien-3-yl)perfluorocyclopentene (1a) and 1,2-bis(2-methyl-5-(2,2'-
dicyano-vinyl)-thien-3-yl)perfluorocyclopentene (2a), as recording medium. Two laser beams of 532 and 780 nm were
used in recording and readout simultaneously, and signals with high S/N ratio were obtained. The results showed that the
two diarylethenes had responded rapidly upon irradiation of the corresponding wavelength laser. The destruction of the
readout and the photochromic properties of the two diarylethenes in PMMA film were also investigated.
Birefringence index-guiding photonic crystal fibers
Show abstract
Based on typical triangular arrangement of air holes with equivalent diameter size, enlarging eight air holes of arranged
in the diamond shape closing to the core of photonic crystal fiber (PCF) to form asymmetry structure of section, this kind
of peculiar arrangement of air holes in inner-cladding can make modal field present some birefringence character and
birefringence degree can be obtained at the magnitude of 10-4. Here, a series of characters about designed PCFs, such as
modal field, dispersion, effective refractive index in two orthogonal directions, and birefringence are investigated.
The exact validation for measuring the electro-optic coefficients of organic/inorganic hybrid material film
Show abstract
Exact expressions for calculating the electro-optic (EO) coefficients of GaAs and polymer or organic/inorganic hybrid
film using simple reflection technique have been deduced. For different approximate conditions, several expressions
have been contrasted. After strictly verified, the measuring systems are accurately adjusted, and with the measured data
the numerical value of
γ33 can be calculated. The measured EO coefficient of GaAs is in excellent agreement with the
known value. The organic/inorganic hybrid material is prepared by sol-gel process during which dispersed red 1 (DR1) is
doped in tetraethoxysilane (TEOS) as the chromophore with a concentration of approximately 13% by weight. And
γ33
of hybrid material over 20pm/V could be easily obtained.
The comparison of two kinds of fiber phase shifting point-diffraction interferometer
Show abstract
The point diffraction interferometer (PDI) is the technology which realizes the absolute interferometric measurement
without the use of reference surface. Pinhole is mostly used to generate the ideal spherical wavefront traditionally. While
using the single mode optical fiber instead of pinhole can easily introduce phase-shifting ability for PDI measurement.
This paper mainly discusses the merits and disadvantages of two kinds of fiber phase shifting point diffraction
interferometer (FPS/PDI). Two fibers FPS/PDI is a separated-path configuration. Although it's easy to adjust, it's more
sensitive to environment influence, and the thickness of fiber cladding will induce an off-axis error during measurement.
Single fiber FPS/PDI is a common-path configuration, thus it is robuster than the front, but the maximum visibility is
now one half. Its accuracy is mainly affected by factors such as the fiber core diameter, slight ellipticity and oblique face.
The paper lastly compares the single fiber PDI with ZYGO interferometer based on measurement data about a sphere
surface, the single interference pattern collected by our experimental fiber PDI apparatus is analyzed and the major error
sources are also discussed.
Shape effect on nonlinear optical properties of CdS nanorod and nanoparticle films
Show abstract
The third order nonlinear optical properties of CdS nanorod film and CdS nanoparticle film were investigated
comparatively by using nanosecond laser pulses at 532 nm. It is observed that the values of the nonlinear refractive index
n2 (23×10-11 esu), the nonlinear absorption coefficient β (4.4×10-11 m/W) and the effective third order nonlinear
susceptibility )
χ(3)eff (1.7×10-11 esu) of CdS nanorod film are larger than CdS nanoparticle film (5.2×10-11 esu, 3.9×10-11
m/W, 1.4×10-11 esu). Experimental results show that the shapes of CdS nanomaterials have effect on their third order
nonlinear optical properties. The results were analyzed by use of the Maxwell-Garnett Effective Medium theory (MGT).
A novel microstructured optical fiber with high birefringence
Show abstract
High birefringence optical fibers such as elliptical core fibers and many highly birefringent photonic crystal fibers
usually broke the symmetry of circle by introduced C2ν symmetry. In this paper, a novel microstructured high
birefringence optical fiber with C1ν symmetry is proposed. Four air holes were introduced into the core of a circular
optical fiber, circular symmetry was broken, and the core of this kind of optical fibers only maintained C1ν symmetry.
The degeneracy fundamental mode LP01 was split into two modes LPx01, LPy01 because the symmetry of C1v is lower than
that of C2ν , the difference between the patterns of the two modes field was larger. Using multipole method, we
calculated the propagation constants of modes LPx01 and LPy01, the modal birefringence B is to the magnitude of 10-2
which is almost tenfold greater than that of many highly birefringence photonic crystal fibers. The other advantage of
this kind of optical fibers is that the fabrication of fibers with a few air holes is easier than that of photonic crystal fibers
with many air holes.
The evolution of polarization state in two-mode optical fibers
Show abstract
Two-mode optical fibers have been studied extensively for telecommunication device and sensor application. This paper
investigates the evolution of polarization state in two-mode optical fibers. Two-mode Fibers usually support four modes,
i.e.
LPx01,
LPy01,
LPx11(even),
LPy11(even). The propagation constants of the four modes are different so that the polarization
state of an incident light will not maintain when the light propagating along the fiber. The evolution of the polarization
state in a two-mode optical fiber is analyzed in theory, the result shows that unlike a conventional highly birefringent
optical fiber, the polarization state of the incident light is not recurred at any length of the fiber; i.e. strictly speaking, the
beat length is not existed in a two-mode optical fiber. However, the every modal birefringence index of two modes can
be found by a wavelength scanning method. The power of the output light in a special polarization direction is detected;
it is a multi-cycle function, which depends on the wavelength of the incident light. Six periods can be given by using the
Fourier transform spectrum of the output light; they are in direct proportion to modal birefringent indices and the fiber
length, so three modal birefringence indices can be got. It is a most important property of the two-mode optical fibers for
device and sensor application.
Experimental investigation of the fringe pattern of capillary tube filled with liquid by using focused laser sheet of light
Show abstract
A focused laser light sheet was used to illuminate the capillary tube filled with liquid and fringe patterns can be seen.
The fringe patterns can be formed by rays directly passing through the capillary tube or reflected one time or two times
by the walls of the capillary tube then transmitted again. The fringe patterns formed by transmission light lie before the
capillary tube and can be bell-shaped, steep bell-shaped, or almost parallel, which strongly depend on the position of the
capillary tube. The bell shaped pattern can be qualitatively explained by the addition of diffraction of multi-slits and is
relative to the aberration of the cylindrical lens. This pattern is also relative to the refractive index of liquid containing in
the capillary tube. The fringe patterns caused by reflected light lie before or after the capillary tube, which will influence
the contrast of the bell shaped fringe pattern formed by transmitted light.
Design method of a binary optical element for collimation of high-power LD beams with astigmatism
Show abstract
Owing to its compactness, lightness, and low cost, laser diodes (LD) play an important role as a coherent source in
various fields of technology. Because of the waveguide properties of their active areas, laser diodes generate large
divergence-angle beams with elliptically shaped intensity profiles. And the beam of LD has astigmatism. So it is difficult
to collimate LD beams effectively. The binary optical elements are small, light, easy to be copied and able to realize
multi-purpose integrated, especially suits for the beam shaping of laser diode array. Based on accurate far-field model of
high-power laser diode, a design method of binary optical element for laser diode beams, which can correct the
astigmatism of the laser beam, has been developed, and the principle and process has been given in detail. The method is
simple and practical. The relief surface of the element is of multiphase structure. And its theoretical diffraction efficiency
is as high as 95%.
Research on surface topography of MEMS micromirror based on 3D Weierstrass-Mandelbrot function
Yuan Luo,
Yi Zhang,
Xiaodong Xu
Show abstract
Micro-mirror is the key structure of MEMS optical switch, Digital Mirror Display (DMD) and variable optical
attenuators. Surface roughness plays a crucial rule in reflectivity, insertion loss, and all kinds of surface forces. In this
paper, a silicon based non-silicon MEMS optical switch is fabricated and the topographies of various micro-mirror
surfaces are measured by Scanning Tunneling Microscope (STM). After fractal analysis, a three-dimensional
Weierstrass-Mandelbrot function is applied to simulate the topography of different surfaces. The result shows that the
surface of MEMS micromirror which fabricated by metal sputter has low anisotropism and the W-M function is very
efficient in creating models and is very useful in analysis the topography of MEMS surface.
A novel infrared mono-station passive location algorithm based on a mobile platform
Show abstract
A novel infrared mono-station passive location algorithm for a maneuvering target is presented based on infrared
imaging, series images processing and three dimensional movement analysis. The algorithm results in the relative
distance between the maneuvering target and the measurement station by using the measured information of infrared
imaging target. It accurately reflects the actual situation of complex relative movement between the mobile target and the
mobile measurement platform, effectively overcomes the bad influence of the gesture change in the target itself and the
pseudo-gesture change in the target caused by the relative movement between the mobile measurement platform and the
mobile target on ranging precision, objectively reflects the various actual states on the complex relative movement
between the mobile measurement platform and the mobile target. It is applicable to such relative motion models between
the maneuvering target and the maneuvering measurement station as the invariable velocity, invariable acceleration and
variable acceleration and so on with high location precision, small cubage and great mobility. The correctness and
validity of the algorithm are illustrated by both the computer digital simulation and the semi-practicality visible light
imaging simulation. Under the conditions of satisfying the measurement precision requirements on the image and angle
parameters of the target, the relative error of measuring distance is not larger than 5%. At the same time, the algorithm is
also suitable for visible light mono-station passive location.
Damage in sensitive BSO-based asymmetric spatial light modulator
Xiujian Li,
Jiankun Yang,
Juncai Yang,
et al.
Show abstract
Some damages may occur when sensitive BSO (Bi12SiO20) asymmetric spatial light modulators operate in some given
modes, even though the power of the writing light beam is far less than the optical damage threshold. According to some
experimental results and corresponding analysis, high voltage and given operating modes may lead to too high intensity
photocurrent pulse in short time, consequently large quantity of heat in ultra-small area may make the narrow areas swell
up and thus the damage of the BSO film. In order to get well sensibility, well resolution and well response speed without
damages of the spatial light modulators, optimizing the structure parameters and the operating modes is necessary.
Research on crop and weed identification by NIR spectroscopy
Show abstract
Crop and weed identification is very importance in precision farming field. As spectroscopy can reflects the contents of
object tested, so it is possible to identify crop and weed with high correct rate. ASD FieldSpec recorded the spectrum of
crops and weeds. Its waveband is 325-1075nm and with resolution of 3.5nm. One crop seedling and three kinds of weeds
living together were tested. Each species has at least 30 sampling spectrum taken down. As one sample spectrum has too
much data, wavelet transform reduced the data volume firstly, which compressed source signals to tens of floating
numbers from 751 floating numbers. Totally 160 samples were used to build a radial basis function neural network, the
object output was a 4 by 1 dimension vector. Those left 43 samples used to check the identifying capability. As neural
network model has huge power in solving these pattern recognition problems. It can approach to giving finite function at
any approximation. Nearly all these predicting samples classified right. Therefore, by using spectroscopy in the
identification is possible, and having high correct rate. Further more, the computation is very fast. Whereas the
spectrometer is expensive and easily affected by shaking and variation of light shine, it cannot installed directly on
vehicles at present time. In the future, it may be possible to recognize crop and weed in real time by using spectroscopy.
The theory analysis and experiment measure of lateral optical trapping force
Yanying Zhu,
Qiujuan Gao,
Yong Wei
Show abstract
In non-equality optical field, we use the RO model, which is based on the theory of geometric optics, the optical trapping
force which is in Y axes way on the micro sphere particles in the Mie scattering field is calculated quantitatively. The
simulation results under given parameters are described. According to the simulation results, the relations between the
optical trapping force and the main parameters of the system, including focus corset radius and the laser wave-length are
discussed.
Large electro-optic effect in sol-gel-processed poled Ti02/Si02 films doped with organic azo dye
Show abstract
Highly transparent TiO2/SiO2 films prepared using sol-gel technique doped with organic azo dye, Disperse Red 1(DR1)
have been investigated. Processing parameters such as spin speed, spin time, and ambient atmosphere, and solution
synthesis parameters such as catalysis method, alcohol dilution ratio, and component molar percentages, may affect the
film formation. The refractive index increases follow along with the raising of the molar ratio between TiO2 and SiO2.
When the molar ratio between TiO2 and SiO2 is zero, i.e. no titania precursor in the initial solution, the refractive index is
minimum 1.49 at 1300nm, whereas when there is no TEOS in the initial solution, the refractive index is maximum 1.81
at 1300nm. The sol-gel thin film is spin-coated on ITO glass substrate with better uniformity. The electric-optic
coefficient γ33=42pm/V was measured by simple reflection technique at a fundamental wavelength of 1300nm. The
hybrid organic-inorganic sol-gel film is well balanced material in its simplicity for film formation, nonlinearity, and
thermal stability sufficient for device fabrication. Moreover, the measurement system was calibrated and the measured
electric-optic coefficient of the gallium arsenide crystal is in excellent agreement with the known value.
Novel optic fiber voltage sensor based on interference between modes
Show abstract
This paper investigates the principle of interference between modes in fiber, and gives the relationship between
interference of LP01 and LP11even mode and the axial length variety in ideal fiber. A novel scheme of voltage
transducer based on interference between modes is brought out. A PANDA fiber wrapped quartz crystal sandwiched with
two pieces of metal electrodes works as sensing interferometer. When voltage is applied on the metal electrode,
circumference of quartz crystal will change. This can modulate the light path difference of LP01 and LP11even mode in
fiber. A receiving interferometer balances the light path difference with a fiber wrapped piezoelectric ceramics and a
phase tracer. Control voltage of the receiving interferometer is output signal of the transducer. Simulation result and
adjusting method of dynamic range is given in the paper. It can provide a new method for designing voltage transducers.
The study of optical trapping force from optical tweezers
Yanying Zhu,
Mingli Wang
Show abstract
Optical tweezers use the forces exerted by a strongly focused beam of light to trap and move objects ranging in size from
tens of nanometers to tens of micrometers. Since their introduction in 1986, the optical tweezers has become an
important tool for research in the field of biology, physical chemistry and so on. So the study and measure of optical
trapping forces are important currently, and those are also helpful for the development of optical tweezers. At present the
theoretical model has been established about the calculation method of optical tweezers. This document shows a method
of optical tweezers on axis. The optical trapping force was measured and estimated in experiment.
The theoretical model of optical trapping force on axis is different with different size particle. One is Mie particle which
size is much larger than the laser wavelength. We can calculate the optical trapping force by the theoretical model based
on geometrical-optics. Another is Rayleigh particle which size is much smaller than the laser wavelength. We can
calculate the optical trapping force by the theoretical model based on electromagnetics. A method was presented mainly
about the calculation of optical trapping force on axis in this document. Under given parameters, the numerical
simulation of the optical trapping force on particle was demonstrated. And the important impacts of the parameters were
discussed including the radius of the beam waist, the laser wavelength, the laser power, particle radius and so on.
Through the numerical simulation, they have the close relation between the different system parameters and the optical
trapping force. The optical trap will change shallow along with the radius of the beam waist increasing. On the contrary,
the optical trap will change deep along with the laser power increasing. They have a best optical trap scope between the
laser wave length and the particle radius. Thus, we can choose the appropriate parameters in the experiment to obtain the
best optical trapping force.
We captured and moved a particle by a strongly focused beam of laser in experiment. In order to obtain the escaping
speed, we control platform steadily and record the entire capture process through the CCD imaging system. Figuring out
the escaping speed from the known two time interval and the granule displacement value, we can estimate the optical
trapping force by Stocks formula.
A scale distortion invariant pattern recognition with fractional matching filter correlation
Jun Li,
Bin He,
Guang-zhi Fu,
et al.
Show abstract
Two optical units who are constructed by one Fresnel transform and one lens can produce a scale fractional Fourier
transform. The constraints between the tow units are analyzed. Based on that and fractional correlation theory, a scale
distortion invariant pattern recognition method is proposed. Simulation results show that when a scale distortion input
image can't be rightly recognized by the conventional correlation, it can be recognized well with the method. Deficiency
of the method is that lots of matching filters are needed.
Research on encode technology for aspherical surface measurement based on real-time hologram
Show abstract
The aspherical measuring technology that based on computer-generated hologram (CGH) was introduced. The advantage
of this method is that the phase shifts can be controlled digitally, no any mechanical moving and rotating element. By
changing CGH coding which displayed on the Liquid Crystal Display (LCD), the wavefront and phase shifts in
measuring system were induced. Based on the characteristics of aspherical measurement and LCD structure, the CGH
encode technology used in LCD was discussed. Then a new encode method which applied to aspherical measurement
was put forward. In this method, the LCD modulates functions of amplitude and phase was coexistent, and the character
of LCD diffraction frequency spectrum was considered, and phase hologram was applied. This aspherical measuring
technology is more flexible than usual method. In this paper, the hologram encode method based on LCD were
illuminated in detail. In order to verify the correction of encode technology, the aspherical surface with standard
wavefront was generated by coaxial hologram reconstruct system when hologram encode image was displayed on SONY
LCX023 LCD, it interfere with the standard spherical wavefront, then the interferogram was sampled to computer by
Charge Coupled Device (CCD) and A/D transfer, the wavefront of hologram reconstruct was obtained by image process
finally. All calculation is completed by Matlab. An aspherical measuring system based on LCD was built experimentally.
Both the theoretical analysis and experimental results demonstrate the feasibility of this approach.
A matching method based on valid invariant feature part
Show abstract
The target tracking method based on correlation in image sequence is always invalid because of the magnitude or shape
distortion and occlusion. In this paper a robust and highly accuracy matching algorithm called Matching Based on Valid
Invariant Feature Part (MBVF) is proposed, which combines the target image invariant feature description, matching of
feature, and recognition of valid feature. The feature descriptor is formed from a vector containing the values of all the
grad magnitude and orientation entries that belong to the divided parts of target area. The features is robust to image
rotation, distortion, addition of noise, change in 3D viewpoint, and change in illumination. The first step of the algorithm
is to build the invariant feature descriptor of the target area in the referenced image. At the second step, a coarse position
of the target is calculated using the traditional forecast and correlation method. And the invariant feature descriptors of
all the possible points of the tracked target in image to be tracked are built also. Next, by comparing the invariant feature
of the referenced target and the tracked target the valid feature parts of the feature are recognized. At last, similitude
function is calculated according the valid feature parts in both images, which give the final fine position of the target in
the tracked image. Experiment results show that the MBVF can deal with the target tracking and positioning problems in
image sequence process and stereo image analysis automatically and accurately.
Poster Session: Opto-Mechanical High-Speed Cameras
Numerical prediction on static and dynamic properties for rotating mirror of ultra-high-speed photography
Show abstract
The methods of numerical analysis for the strength and vibration modals of rotating mirrors were presented based
respectively on the three-dimensional elastic mechanics and dynamics. On strength computation, the finite element
models of rotating mirror were established according to the real structure of mirror, and the rotating three-faced
aluminous and beryllium mirrors were analysed contrastively. Results display that the surface deformation quantity of the
aluminous mirror is approximately 20 times as large as beryllium one, and the maximum stress is 1.6 times against the
latter. Then, the three-faced aluminous mirrors were analyzed at variedly fit between shaft and axle hole. One conclusion
is gotten out that the mirror strength is foreign to fits, but it is weaken by the axle hole obviously. On the modal analysis
of vibration, this method can simulates accurately the natural frequencies and corresponding modalities of mirror. And
the results from three-face aluminous mirror indicate that the resonance points of a new mirror may be guaranteed
existing in selected speed range.
Numerical simulation on surface deformation for rotating mirrors of ultra-high-speed photography
Show abstract
The numerical analysis method for the surface deformation of rotating mirrors were presented based on the
three-dimensional elastic mechanics and the computational techniques of finite element in this manuscript. With this
method, the surface deformation curves of rotating mirrors including multi-surfaces from three to eight, aluminous, steel,
and beryllium ones were calculated. A result was obtained that surface patterns of a mirror in operation are primarily
dependent on the amount of surfaces and the axial hole which whether or not exists for aluminous and steel mirrors, but
it rests with the amount of surfaces as well as Poisson's ratio for a beryllium mirror with so tiny Poisson's ratio. This
conclusion is different from that of forerunner.
Additional Papers
The granulated gold-film-based semitransparent photocathodes in the visible spectrum range for femtosecond time-resolution experiments
Show abstract
Developed is the granulated, Au film-based, semitransparent photocathode consisting of spherical Au nanoparticles.
The granulated Au films are activated by a thin layer of cesium and oxygen of about two monolayer thicknesses to
decrease the work function down to about 1 eV and gain the photoemission effect in the visible spectrum range. The
sensitivity maximum equal to about one mA/W is located in the green spectrum range. The nanoparticles formation and
photocathode surface structure are studied with the use of the X-ray photoelectron spectroscopy technique. Those studies
have shown that the photoemission effect in the wavelength range &lgr;> 450 nm is conditioned by excitation of the surface
plasmons in quasi-spherical Au nanoparticles. This has allowed manufacturing of a streak tube with the introducible, Au
nanoparticles-based photocathode, stability of which has been remaining invariant.
The results of computer and experimental studies on compressing the ultrashort photoelectron bunches with time-dependent electric fields
Show abstract
Some theoretical milestones, in definite sense summarizing our studies on temporal compressing of photoelectron
bunch with time-depending electric fields, are elucidated. The recent experimental results on dynamic compression of
photoelectron bunches of picosecond duration, gained with the use of a newly designed photoelectron gun employing the
electric field ramp of about 1.5 kV/ns, are presented and compared with the results of computer simulation.
Numerical estimation of space-charge interaction in ultrashort electron bunches
Show abstract
Space-charge interaction effect in ultrashort electron bunches is considered. It is shown that, along with the
already known possibility of effective (first-order) temporal focusing, the time-depending electric fields offer the
advantage of partial compensating for space charge effects in the bunch, which, in turn, seems most promising from the
viewpoint of dynamic range increase in photoelectron tubes and diffractometers.
The up-to-date approaches to femto-attosecond photoelectron imaging
Show abstract
General overview of the past and present, and a look to the future of high-speed image-tube photography are
presented. It is emphasized that it was in Russia that the truly first image-converter tubes were specially designed for the
needs of high-speed photography more than half a century ago. In the middle of the fifties E.K Zavoisky and S.D.
Fanchenko conducted the very first investigations of ultra-high frequency electrical discharge with experimentally
reached and tested 10 ps time resolution, and theoretically predicted the 10 fs ultimate time resolution threshold for high-speed
image-tube photography. Our own, almost half a century long, laser-oriented researches in this area have
confirmed better than 100 fs time resolution in high-speed image-tube photography as well as theoretical possibility of
photoelectron bunch compressing down to the sub-femtosecond level.