This PDF file contains the front matter associated with SPIE Proceedings Volume 7875, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

To develop an ultrahigh-definition television (UHDTV) camera-with a resolution 16 times higher than that of HDTV resolution and a frame rate of 60 Hz (progressive)-a compact and high-mobility UHDTV camera using a 33M-pixel CMOS image sensor to provide single-chip color imaging was developed. The sensor has a Bayer color-filter array (CFA), and its output signal format is compatible with the conventional UHDTV camera that uses four 8M-pixel image sensors. The theoretical MTF characteristics of the single-chip camera and a conventional four-8M-pixel CMOS camera were first calculated. A new technique for Bayer CFA demosaicing used for the single-chip UHDTV camera was then evaluated. Finally, a pick-up system for single-chip imaging with a 33M-pixel color CMOS image sensor was measured. The measurement results show that the resolution of this is equivalent to or surpasses that of the conventional four-8M-pixel CMOS camera. The possibility of a practical compact UHDTV camera that makes use of single-chip color imaging was thereby confirmed.

In the past few years there has been a significant volume of research work carried out in the field of multispectral image acquisition. The focus of most of these has been to facilitate a type of multispectral image acquisition systems that usually requires multiple subsequent shots (e.g. systems based on filter wheels, liquid crystal tunable filters, or active lighting). Recently, an alternative approach for one-shot multispectral image acquisition has been proposed; based on an extension of the color filter array (CFA) standard to produce more than three channels. We can thus introduce the concept of multispectral color filter array (MCFA). But this field has not been much explored, particularly little focus has been given in developing systems which focuses on the reconstruction of scene spectral reflectance. In this paper, we have explored how the spatial arrangement of multispectral color filter array affects the acquisition accuracy with the construction of MCFAs of different sizes. We have simulated acquisitions of several spectral scenes using different number of filters/channels, and compared the results with those obtained by the conventional regular MCFA arrangement, evaluating the precision of the reconstructed scene spectral reflectance in terms of spectral RMS error, and colorimetric ▵E*_ab color differences. It has been found that the precision and the the quality of the reconstructed images are significantly influenced by the spatial arrangement of the MCFA and the effect will be more and more prominent with the increase in the number of channels. We believe that MCFA-based systems can be a viable alternative for affordable acquisition of multispectral color images, in particular for applications where spatial resolution can be traded off for spectral resolution. We have shown that the spatial arrangement of the array is an important design issue.

LCD displays exhibit significant amount of variability in their tone-responses, color responses and backlight-modulation responses. LCD display characterization and calibration using a spectrometer or a color meter, however, leads to two basic deficiencies: (a) It can only generate calibration data based on a single spot on the display (usually at panel center); and (b) It generally takes a significant amount of time to do the required measurement. As a result, a fast and efficient system for a full LCD display characterization and calibration is required. Herein, a system based on a 3CCD calorimetrically-calibrated camera is presented which can be used for full characterization and calibration of LCD displays. The camera can provide full tri-stimulus measurements in real time. To achieve high-degree of accuracy, colorimetric calibration of camera is carried out based on spectral method.

Optimizing quantum efficiency of image sensors, whether CCD or CMOS, has usually required backside thinning to bring the photon receiving surface close to the charge generation elements. A new CMOS sensor architecture has been developed that permits high-fill-factor photodiodes to be placed at the silicon surface without the need for backside thinning. The photodiode access provided by this architecture permits application of highly-effective anti-reflection coatings on the input surface and construction of a mirror inside the silicon below the photodiodes to effectively double the optical thickness of the silicon charge generation volume. Secondary benefits of this architecture include prevention of light from reaching the CMOS circuitry under the photodiodes, improvement of near-infrared quantum efficiency, and reduction in optical artifacts caused by reflections from the sensor surface. Utilizing these techniques, a sensor is being constructed with 4096 x 4096 pixels 4.8 μm square with 95% fill factor backed by a mirror tuned to the 400-700 nm visible band and a front-surface anti-reflectance coating. The quantum efficiency is expected to exceed 80% through the visible and the global shutter extinction ratio should exceed 10⁶:1. The sensors have been fabricated and first test data is due in February 2011.

e2v technologies has developed "Hi-Rho" devices manufactured on very high resistivity silicon. Special design features have been included that enable extremely high gate to substrate potentials to be applied without significant current leakage between back and front substrate connections. The approach taken allows the usual design rules for low noise output amplifier circuitry to be followed. Thus low noise devices very sensitive to red and near infrared wavelengths can be manufactured. This paper reports on the detailed characterisation of the large format "Hi-Rho" sensor designed for astronomical applications and extends the data previously reported to include detailed assessment of the CTE, spatial resolution, dark signal and cosmetic quality. The influence of the base material has also been investigated with devices manufactured on silicon from two different manufacturers. Measurements of the quantum efficiency from devices utilising a newly developed antireflection coating process are presented.

Classic photo gate APS uses a MOS capacitor that can capture incident illumination with a potential well created under the photogate. The major drawback of such a technology is the absorption of shorter wavelength by the polysilicon gate resulting in a higher sensitivity in the red visible spectrum than in the blue range. To reduce this we previously had experimentally shown that a multifinger photo gate APS designs with 0.72Νm fingers implemented in the 0.18 μm CMOS technology have a significant increase in sensitivity of 1.7 times the standard photo gate APS. Using advanced 2-dimensional device simulations had shown that the fringing fields form the these fingers would create a potential well shape that approached that of the standard fully covered photo gate, but with large open areas which would have less optical absorption. Reducing the gate widths resulted in higher efficiency of photo carriers generated in the larger open areas while keeping the potential well shape desired. In this work, we use optical simulation package on the 2D device simulation tools to simulate the multi finger photo gate designs with white light illumination. Sensitivity of the pixel is calculated as the count of total number of photocarriers that are collected by the potential well for a given exposure cycle. All the multifinger designs achieved a significant increase in efficiency with respect to the standard photogate APS design, with the peak sensitivity of 550% by the 7finger design with a gate width of 0.25μm.

Multi-aperture imaging systems inspired by insect compound eyes promise advances in both miniaturization and cost reduction of digital camera systems. Instead of a single lens stack with size and sag in the order of a few millimeters, the optical system consists of an array of microlenses. At a given field of view of the complete system, the focal lengths of the microlenses is a fraction of the focal length of a single-aperture system, reducing track length and increasing depth of field significantly. As each microimage spans only a small field of view, the optical systems can be simple. Because the microlenses have a diameter of hundreds of microns and a sag of tens of microns, they can be manufactured cost-effectively on wafer scale and with high precision. However, reaching a sufficient resolution for applications such as camera phones has been a challenge so far. We demonstrate a multi-aperture color camera system with approximately VGA resolution (700x550 pixels) and a remarkably short track length of 1.4 mm. The algorithm for correcting optical distortion of the microlenses and combining the microimages into a single image is the focus of this presentation.

This paper describes the design of analog circuitry to implement logarithmic number system (LNS) subtraction. Such circuitry, if incorporated in the readout circuitry of a logarithmic CMOS image sensor, would allow for the on-chip calculation of spatial derivatives, while operating directly on logarithmically-scaled pixels. The circuit was implemented for a 1.2μm CMOS process. The maximum relative error at the output of the LNS subtractor for pixel currents that correspond to an illumination range of more than four decades is 4.26%.

Fluorescence lifetime imaging is becoming a powerful tool in biology. A charge-domain CMOS Fluorescence Lifetime Imaging Microscopy (FLIM) chip using a pinned photo diode (PPD) and the pinned storage diode (PSD) with different depth of potential wells has been previously developed by the authors. However, a transfer gate between PPD and PSD causes charge transfer noise due to traps at the channel surface. This paper presents a time-resolved CMOS image sensor with draining only modulation pixels for fluorescence lifetime imaging, which removes the transfer gate between PPD and PSD. The time windowing is done by draining with a draining gate only, which is attached along the carrier path from PPD to PSD. This allows us to realize a trapping less charge transfer between PPD and PSD, leading to a very low-noise time-resolved signal detection. A video-rate CMOS FLIM chip has been fabricated using 0.18μm standard CMOS pinned diode image sensor process. The pixel consists of a PPD, a PSD, a charge draining gate (TD), a readout transfer gate (TX) between the PSD and the floating diffusion (FD), a reset transistor and a source follower amplifier transistor. The pixel array has 200(Row) x 256(Column) pixels and the pixel pitch is 7.5μm. Fundamental characteristics of the implemented CMOS FLIM chip are measured. The signal intensity of the PSD as a function of the TD gate voltage is also measured. The ratio of the signal for the TD off to the signal for the TD on is 212 : 1.

We have reviewed the development of the biosensor based on imaging ellipsometry including its principle, methodology and general engineering model structure, mainly compared experimental setups between the previous one and the recently developed one. It's obvious that the sensitivity and the signal to noise ratio has been improved by a various spectroscopic light source, the optimization of polarized components setting and a cool CCD, especially the contribution of the CCD, which makes the biosensor available in more and more biomedical applications.

We analyze the "ageing" effect on image sensors introduced by neutrons present in natural (terrestrial) cosmic environment. The results obtained at sea level are corroborated for the first time with accelerated neutron beam tests and for various image sensor operation conditions. The results reveal many fascinating effects that these rays introduce on image sensors.

It is generally assumed that charge-coupled device (CCD) imagers produce a linear response of dark current versus exposure time except near saturation. We found a large number of pixels with nonlinear dark current response to exposure time to be present in two scientific CCD imagers. These pixels are found to exhibit distinguishable behavior with other analogous pixels and therefore can be characterized in groupings. Data from two Kodak CCD sensors are presented for exposure times from a few seconds up to two hours. Linear behavior is traditionally taken for granted when carrying out dark current correction and as a result, pixels with nonlinear behavior will be corrected inaccurately.

Image sensors are continuously subject to the development of in-field permanent defects in the form of hot pixels. Based on measurements of defect rates in 23 DSLRs, 4 point and shoot cameras, and 11 cell phone cameras, we show in this paper that the rate of these defects depends on the technology (APS or CCD) and on design parameters the like of imager area, pixel size, and gain (ISO). Increasing the image sensitivity (ISO) (from 400 up to 25,600 ISO range) causes the defects to be more noticeable, with some going into saturation, and at the same time increases the defect rate. Partially stuck hot pixels, which have an offset independent of exposure time, make up more than 40% of the defects and are particularly affected by ISO changes. Comparing different sensor sizes has shown that if the pixel size is nearly constant, the defect rate scales with sensor area. Plotting imager defect/year/sq mm with different pixel sizes (from 7.5 to 1.5 microns) and fitting the result shows that defect rates grow rapidly as pixel size shrinks, with an empirical power law of the pixel size to the -2.5. These defect rate trends result in interesting tradeoffs in imager design.

Negative bias on transfer gate in 4-transistor CMOS imager pixel is an efficient way to reduce dark current generated at the Si-SiO2 interface. But further lowering of negative bias increases dark current noise. In this paper, detailed cause analysis of dark current noise generated when negative bias is applied and the key technology to reduce the dark current noise are shown. The dark output level of hot pixel follows a Trap-Assisted-Tunneling (TAT) dark current electric field dependency. Device simulation shows that the generation of high electric field is attributed to the large voltage difference between the high concentration hole accumulation layer under negatively biased transfer gate and n- layer of FD edge along transfer gate. The reduction of dark current in FD is experimentally observed when the n- dopnat concentration at FD edge is decreased and when a gate insulator thickness is increased. The results show that the mechanism of the dark current increase is Gate-Induced-Leak (GIL) TAT generated by high electric field at the edge of a FD along negatively biased transfer gate. The reduction of the maximum electric filed at the FD edge by reducing FD dopant concentration is one of the key to suppress the GIL - TAT dark current.

There is little doubt that the Charge-Coupled Device (CCD) and its cousin the CMOS Active Pixel Sensor (APS) have completely revolutionized the imaging field. It is becoming more and more difficult to obtain film for cameras and digital cameras are available from the cell phone to the professional photographer in multimegapixel format. This paper explores some of the origins of the CCD as a scientific sensor.

Several applications require systems for 3D ranging acquisition, where both high frame-rate and high sensitivity (for either very dark environments or opaque objects) are a must. We exploited a monolithic chip with 32 x 32 Single-Photon Avalanche Diode smart-pixels for 3D ranging applications based on an Indirect Time-of-Flight (iTOF) technique. The scene is illuminated by a sinusoidally modulated LED and the reflected light is acquired by the imager in different timeslots, for measuring the phase delay of outgoing vs. incoming signal, hence computing the distance between the sensor and objects in the scene. All 1024 array pixels are synchronously enabled by a global gate signal, which allows photon counting in well-defined time-slots within each frame. The frame duration is set in accordance to the desired SNR. We report on measurements performed on chips fabricated in a standard high-voltage 0.35 μm CMOS technology, which feature 40% photon detection efficiency at 450 nm and 20% at 650nm. The single-photon sensitivity allowed the use of just few LEDs at 650 nm and 20MHz for acquiring a scene with a maximum distance of 7.5 m, with better than 10 cm distance resolution and frame-rates higher than 50 frames/s.

Scientific experiments often demand the detection of very weak light signals at high-speed or to precisely measure the time of arrival of single photons. Arrays of Single-Photon Avalanche Diodes (SPAD) are ideal candidates when high sensitivity is required together with high frame-rate or precise photon-timing resolution. We designed a linear 32x1 SPAD array using a high-voltage CMOS technology able to provide both good SPAD performance and fast electronics. During frame acquisition all pixels work in parallel, each of them being equipped with anything necessary for photon counting. The array architecture is capable of fully parallel operation of all pixels allowing free running acquisition at high frame-rate. With a low-speed 10 MHz clock frequency, one pixel is read out in 100 ns while the whole array is readout in 320 ns, corresponding to a frame-rate of 312.5 kframe/s. The frame-rate can top to 4 Mframe/s with a clock of 128 MHz. The photon timing modality employs the photon time-of-arrival information provided by each of the 32 outputs. All 32 "timing" outputs feed external Time-Correlated Photon Counting boards. The Full-Width at Half- Maximum using very short laser pulses is 55 ps with few kcps counting rate.

Nano-biophotonics applications will benefit from new fluorescent microscopy methods based essentially on super-resolution techniques (beyond the diffraction limit) on large biological structures (membranes) with fast frame rate (1000 Hz). This trend tends to push the photon detectors to the single-photon counting regime and the camera acquisition system to real time dynamic multiple-target tracing. The LUSIPHER prototype presented in this paper aims to give a different approach than those of Electron Multiplied CCD (EMCCD) technology and try to answer to the stringent demands of the new nano-biophotonics imaging techniques. The electron bombarded CMOS (ebCMOS) device has the potential to respond to this challenge, thanks to the linear gain of the accelerating high voltage of the photo-cathode, to the possible ultra fast frame rate of CMOS sensors and to the single-photon sensitivity. We produced a camera system based on a 640 kPixels ebCMOS with its acquisition system. The proof of concept for single-photon based tracking for multiple single-emitters is the main result of this paper.

We present a novel "smart-pixel" able to measure and record in-pixel the time delay (photon timing) between a START (e.g. given by laser excitation, cell stimulus, or LIDAR flash) and a STOP (e.g. arrival of the first returning photon from the fluorescence decay signal or back reflection from an object). Such smart-pixel relies of a SPAD detector and a Timeto- Digital Converter monolithically designed and manufactured in the same chip. Many pixels can be laid out in a rows by columns architecture, to give birth to expandable 2D imaging arrays for picoseconds-level single-photon timing applications. Distance measurements, by means of direct TOF detection (used in LIDAR systems) provided by each pixel, can open the way to the fabrication of single-chip 3D ranging arrays for scene reconstruction and intelligent object recognition. We report on the design and characterization of prototype circuits, fabricated in a 0.35 μm standard CMOS technology containing complete conversion channels, "smart-pixel" and ancillary electronics with 20 μm active area diameter SPAD detector and related quenching circuitry. With a 100 MHz reference clock, the TDC provides timeresolution of 10 ps, dynamic range of 160 ns and very high conversion linearity.

IEDs kill our soldiers and innocent people every day. Lessons learned from Iraq and Afghanistan clearly indicated that IEDs cannot be detected/defeated by technology alone; human-technology interaction must be engaged. In most cases, eye is the best detector, brain is the best computer, and technologies are tools, they must be used by human being properly then can achieve full functionality. In this paper, a UV Raman/fluorescence, CCD and LWIR 3 sensor fusion system for standoff IED detection and a handheld fusion system for close range IED detection are developed and demonstrated. We must train solders using their eyes or CCD/LWIR cameras to do wide area search while on the move to find small suspected area first then use the spectrometer because the laser spot is too small, to scan a one-mile long and 2-meter wide road needs 185 days although our fusion system can detect the IED in 30m with 1s interrogating time. Even if the small suspected area (e.g., 0.5mx0.5m) is found, human eyes still cannot detect the IED, soldiers must use or interact with the technology - laser based spectrometer to scan the area then they are able to detect and identify the IED in 10 minutes not 185 days. Therefore, the human-technology interaction approach will be the best solution for IED detection.

CD146 glycoprotein belonging to cell adhesion molecules is considered to be a novel target on endothelial cell involved in tumor angiogenesis. The biosensor based on imaging ellipsometry (BIE) which is performed in null and off-null mode is used for CD146 detection as a trial by the following steps. Firstly, anti-CD146 antibody as ligand is immobilized on Protein G modified silicon substrate. Then, CD146 test is carried out and its calibration curve is established for the requirement of quantitative detection. Finally, 18 serum samples are detected quantitatively and their results are validated by ELISA's. The sensitivity for CD146 detection achieves the order of ng/ml and the relationship between BIE signal y (grayscale value) and CD146 concentration x (ng/ml) is y=3.3ln(x) +91.3. Compared with ELISA's, the majority of results are in agreement, and the results of two approaches have significant statistic relevance.

Various approaches have been utilized to extend the dynamic range of the CMOS image sensor, which are based on a linear-logarithmic CIS, overflow integration capacitor and multiple sampling or individual pixel resetting. These approaches, however, suffer from noise, nonlinearity, lower sensitivity, reduced operating speed and lower resolution. In order to overcome these problems, we have previously proposed a dynamic range extension method by combining output signals from two photodiodes with different sensitivities, such as a high-sensitivity photodiode and a low-sensitivity photodiode. The proposed active pixel sensor has been fabricated by using 2-poly 4-metal standard CMOS process and its characteristics have been measured. It is found that charges in the high- and low-sensitivity photodiodes could be mixed each other and the lost image information of the high-sensitivity photodiode could be regenerated using the charges in the low-sensitivity photodiode, as shown by simulation results. Dynamic range extension of the proposed active pixel sensor has been experimentally verified.

High Dynamic Range (HDR) Image sensors aim at having a dynamic over 120dB. Compared to classical architectures this is obtained at the cost of a higher transistor count, thus lower fill factor. Three Dimensional integrated circuits (3DIC) somehow change the constraints, photodiodes and electronics can be stacked on different layers, giving more processing powers without compromising the fill factor. In this paper, we propose an original architecture for a high dynamic 3D image sensor with data reduction obtained by local compression. HDR acquisition is based on a floating point coding shared by a group of pixel (macro-pixel), thus giving also a first level of compression. A second level of compression is performed by using a Discrete Cosine Transform (DCT). With this new concept a good image quality (PSNR of about 40 dB) and a high dynamic range (120 dB) are obtained within a pixel area of 5μm×5μm.

The biosensors with properties of real-time, high throughput and label-free are more and more popular recently, in which the biosensor based on the total internal reflection imaging ellipsometry (TIRIE) is a novel imaging detector for protein interaction processes. In previous work, three techniques are introduced to improve the performance of the biosensor including polarization setting optimization, spectroscopic light source application and low noise CCD detector adoption. In this paper, the effect of the low noise CCD detector technology on the sensitivity and detection limit improvement is analyzed. An obvious improvement of 10 time increase in the sensitivity and SNR, and 50 times lower concentration in the detection limit is obtained by optimization.