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- Front Matter: Volume 7395
- Nano Fabrication and Lithography
- Plasmonic Spectroscopy II
- Nano Imaging I
- Nanosensing
- Manipulation of Plasmonic Effect II
- Plasmonics I
- Plasmonics II
- Plasmonics III
- Plasmonic Metamaterials I
- Plasmonic Metamaterials II
- Plasmonic Metamaterials III
- Nanoplasmonic Applications I
- Nanoplasmonic Applications II
- Poster Session
Front Matter: Volume 7395
Front Matter: Volume 7395
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This PDF file contains the front matter associated with SPIE Proceedings Volume 7395, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.
Nano Fabrication and Lithography
Molecular manipulation and nanofabrication using local polarization in optical near-fields
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We demonstrate nanofabrication of photoreactive azobenzene molecular thin films using optical migration of molecules induced by local polarization in optical near-fields. Transportation and alignment control of the nanomaterial systems were investigated to modulate the excitation of the optical near-fields. Energy transfers from fluorescent molecules were observed along a planar boundary system of metals and dielectrics. The fundamental processes of tunneling energy that flowed to the metallic layer were evaluated from the angular distribution of scattered light in a far field, corresponding to the angular spectrum of scattered fields, including those of evanescent waves excited near the fluorescent molecules and nanostructures fabricated on azo molecular films.
Nanoscale photopolymerization induced by the enhanced optical near field of metallic nanoparticles
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This letter provides a brief summary on early work and developments on both controlling and studying the optical
properties of resonant metal nanoparticles and reports on all progress achieved since two years. Our approach is based on
controlled nanoscale photopolymerization triggered by local enhanced electromagnetic fields of silver nanoparticles
excited close to their dipolar plasmon resonance. By anisotropic polymerization, symmetry of the refractive index of the
surrounding medium was broken: C1v symmetry turned to C2v symmetry. This approach has overcome all the
difficulties faced by scanning probe methodologies to reproduce the form of the near field of the localized surface
plasmons and provides a new way to quantify its magnitude. Furthermore, this approach leads to the production of
polymer/metal hybrid nano-systems of new optical properties.
Fabrication of III-V semiconductor quantum dots
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We propose a method for the fabrication of self-assembled semiconductor quantum dots (QDs) and the control of their
density and emission wavelength. This method would be fundamental toward the fabrication of nanophotonic devices.
We used molecular beam epitaxy and fabricated self-assembled QDs from various materials under various growth
conditions. We controlled the emission wavelength over a wide range (700-1700 nm) by changing the materials around
the QDs. We used antimonide-related materials or a highly stacked structure to control the density of the obtained QDs
within the range of 108-1013/cm2.
Plasmonic Spectroscopy II
Surface plasmon polariton enhanced fluorescence from quantum dots on nanostructured metal surfaces
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Surface plasmon polariton enhanced fluorescence from CdSe/ZnS quantum dots (QD) deposited onto patterned gold/PMMA substrates has been observed. Comparison of gold, chromium, and ITO substrates is used to verify restriction of enhancement effect to surface plasmon polariton supporting materials. Enhanced fluorescence is observed
by using one dimensional gratings defined by electron beam lithography to provide phase matched coupling into surface plasmon polaritons on the metal film surface. Controlled variation of grating parameters is used to examine the dependence of this effect on the periodicity and shape of the coupling grating. Analysis of the results indicates that
strong enhancement requires optimization of both grating periodicity and structure for specific wavelengths and
materials.
Confocal and near-field spectroscopic investigation of P3HT:PCBM organic blend film upon thermal annealing
Show abstract
The poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) organic films are widely
employed as electronic donor and acceptor in the field of organic film solar cell because of their high photovoltaic
conversion efficiency. A home-built parabolic mirror assisted confocal and apertureless near-field optical microscope
was used to investigate the degradation behavior of the film and to distinguish the donor and acceptor domains both
topographically and optically. Under ambient condition, the degradation rates are decreased in the sequence of pristine
P3HT, blend P3HT:PCBM film and pristine PCBM. N2 protection dramatically slows down the film degradation rate.
Using confocal spectroscopic mapping, we are able to distinguish the local distributions of P3HT and PCBM.
Micrometer PCBM aggregates were observed due to the thermal annealing process. Our experimental methods show the
possibility to investigate morphology and the photochemistry properties of the organic solar cell films with high spatial
resolution.
Nano Imaging I
Ultrafast energy flow in hybrid plasmonic materials
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Nanoscale materials absorb, propagate, and dissipate energy very differently than their bulk
counterparts. Furthermore, hybrid nanostructures consisting of molecular and plasmonic materials with
strongly coupled electronic states can produce new optical states and decay pathways that provide additional
handles with which to externally control energy flow in complex nanostructured systems. In this talk, we
discuss our recent studies of electromagnetic coupling and associated temporal dynamics of molecular
excitations with plasmonic resonances supported by either localized or extended planar geometries. Recent
experimental results and theoretical analysis for observing and controlling coherences between molecular
excitations and plasmonic polarizations are shown. Advances will explore new directions in ultrafast
manipulation of energy dissipation processes in hybrid plasmonic structures, as well as ultrafast addressing
and switching in plasmonics-based circuit architectures. Also discussed are recent synthetic advances in the
creation of hybrid materials. Ultimately, these studies may impact a range of next-generation optical materials
and devices, of relevance to new energy conversion materials, nanoscale photocatalysis, or plasmon-enhanced
sensors.
Nanosensing
Plasmonic nanoparticle based biosensing: experiments and simulations
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Shape dependent sensitivity of localized surface plasmon based biosensing was investigated by combining single particle
protein sensing and multiple multipole program simulation. Significantly higher sensitivity was observed for tetrahedral
particles than spherical ones, which was revealed by careful structural analysis of individually measured particles. The
simulation of the corresponding particles with layered protein adsorption model showed consistent optical property and
sensitivity, which were explained in terms of the field enhancement at the pointing edges.
Exploiting plasmonics in biosensing and bioimaging: monitoring cell receptors with surface enhanced spectroscopy and microscopy
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The plasmon resonance of noble metal nanoparticles (NP) manifests itself in a variety of extraordinary optical properties.
Resonant excitation of the conduction electrons by incident radiation generates a localized surface plasmon resonance
(LSPR) that is responsible for a variety of surface enhanced optical phenomena. This unique optical property coupled
with well-established surface chemistry allows us to utilize both Ag and Au NP as optical contrasting agents to probe
and monitor the surface receptors of cells. We have employed two plasmon-assisted optical techniques (namely, surface
enhanced Raman scattering, and resonant Rayleigh scattering) to monitor the adrenergic receptors in mammalian
cardiomyocyte cells that have been labeled with functionalized Ag NPs. In this study, a unique Raman reporter
molecule, 4-(mercaptomethyl)benzonitrile, was developed to provide an easily identifiable vibration, the C≡N stretch, in
a spectral window free from Raman bands of cell constituents and other biomolecules used in receptor crosslinking and
surface passivation. Successfully labeled cells were then monitored with both optical techniques. Both techniques are
related through the plasmonic properties of the noble metal NP and combined with high resolution imaging techniques;
we outline the importance that different NP architectures play in the different imaging techniques. Furthermore, we will
discuss the instrumentation and plasmonic implications in the design of NP best suited for such multimodal imaging
approaches.
Manipulation of Plasmonic Effect II
Control light propagation and polarization with plasmons for surface-enhanced Raman scattering
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Surface plasmon resonances in metal nanostructures can lead to novel optical properties. The greatly enhanced
electromagnetic field makes surface-enhanced Raman scattering (SERS) a highly sensitive spectroscopic technique. We
employed Ag nanowires as plasmonic waveguide and achieved
remote-excitation SERS at a few molecules level. The
junctions between metal nanowires and nanoparticles offer hot spots for SERS, while the enhancement strongly depends
on the laser polarization. We studied the polarization dependence in Au nanowire-nanoparticle systems of different
geometry. The polarization of Raman-scattered light in SERS is a rarely studied topic. We found nanoantennas
composed of a few nanoparticles can manipulate the polarization of emission light. A nanoparticle trimer is the simplest
nanoantenna to realize the polarization control. By tuning the position and size of the third particle, emission polarization
can be modified in a controllable way. In addition, the refractivity of the surrounding media also plays a crucial role for
the emission polarization.
Gap plasmon waveguide with a stub: structure for a wavelength selective device
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We have performed the three dimensional (3D) numerical analysis for a gap plasmon waveguide with two stubs in a
silver film by using the 3D finite-difference time-domain (FDTD) method. The simulated transmittance shows that such
the 3D structure works as a wavelength selective device with submicron size as already predicted in the 2D simulations.
We have also fabricated such a structure on a glass substrate by using the focused ion beam method. The width of the
gap is around 150 nm. The observed transmittance spectra of the structure have clearly indicated the wavelength
dependence and agree well with those obtained by a numerical simulation. Our results show that the structure proposed
by us is promising for a compact wavelength selective device.
Transient surface plasmon polariton launched by a metal subwavelength slit scattering
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We present a rigorous closed-form solution to complete the fundamental theory on the transient surface plasmons
polaritons (SPP) present on a metal interface, in addition to the conventional long-range SPP, launched by scattering of a
metal subwavelength slit. We demonstrate that the Maxwell equations solution includes a transit SPP with complexvalued
Exponential Integral envelope by computing the Sommerfeld branch-cut integrals. Physically, the transient SPP
is the cylindrical wave initially radiated from the source line, which losses its energy to pumping the long-range SPP
mode in the propagation. Its varying damping rate is comparable with existing numerical and approximate results.
Molecular active plasmonics: controlling plasmon resonances with molecular machines
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The paper studies the molecular-level active control of localized surface plasmon resonances (LSPRs) of Au nanodisk
arrays with molecular machines. Two types of molecular
machines - azobenzene and rotaxane - have been demonstrated
to enable the reversible tuning of the LSPRs via the controlled mechanical movements. Azobenzene molecules have the
property of trans-cis photoisomerization and enable the photo-induced nematic (N)-isotropic (I) phase transition of the
liquid crystals (LCs) that contain the molecules as dopant. The phase transition of the azobenzene-doped LCs causes the
refractive-index difference of the LCs, resulting in the reversible peak shift of the LSPRs of the embedded Au nanodisks
due to the sensitivity of the LSPRs to the disks' surroundings' refractive index. Au nanodisk array, coated with
rotaxanes, switches its LSPRs reversibly when it is exposed to chemical oxidants and reductants alternatively. The
correlation between the peak shift of the LSPRs and the chemically driven mechanical movement of rotaxanes is
supported by control experiments and a time-dependent density functional theory (TDDFT)-based, microscopic model.
Plasmonics I
Sensitivities and amplification of surface plasmons
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This paper discusses two aspects of current interest in surface plasmon photonics: the surface
sensitivity of surface plasmon waveguides, and the amplification of surface plasmon-polaritons via
propagation through an optically pumped dipolar gain medium incorporated into one of the
claddings. Physically realisable structures are considered in both cases.
Plasmonics: nonlinear optics, negative phase, and transformable transparency
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The feasibilities and specific features of coherent nonlinear-optical energy transfer from control fields to a negativephase
signal are studied, and they are found to stem from the backwardness of electromagnetic waves inherent
to negative-index metamaterials. Plasmonic metamaterials that possess negative group velocity for light waves
promise a revolutionary breakthrough in nanophotonics. However, strong absorption inherent to such metaldielectric
nanocomposites imposes severe limitations on the majority of such applications. Herein we show the
feasibility and discuss different nonlinear-optical techniques of compensating such losses, producing transparency,
amplification and even generation of negative-phase light waves in originally strongly absorbing microscopic
samples of plasmonic metal-dielectric nanostructured composites.
Plasmonics II
Coupling light to a localized surface plasmon-polariton
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We investigate the interaction of focused Gaussian and
radially-polarized beams with a silver nanosphere, with
emphasis on the coupling to localized surface plasmon-polaritons. We discuss the overall efficiency, including
the effect of the entrance pupil and of absorption in the nanosphere, showing that a Gaussian beam performs
better than a radially-polarized beam, when focused by an aplanatic system. We find that more than 50% of
the photons in the incident beam can be reflected using realistic focusing parameters.
Plasmonics III
Nanoparticle optics of complex nanorod architectures
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Computational studies on the optical properties of nanorods with unique compositions and exotic surface
structure are presented. The distinctive architectures investigated-and compared to smooth Au rods-include
Ni/Au multiblock rods and nanoporous Au rods. The surface plasmon resonances are extremely dependent
upon the morphology and makeup of the nanorods. For a rod with a given aspect ratio, the resonance structure
is sensitive to attributes such as the size of Ni sections of multiblock rods and pore structure of nanoporous
rods. These studies indicate that control of the optical properties of nanorods is possible via characteristics
other than the aspect ratio and suggest that a broader range of tunability is attainable.
Modeling near-field properties of plasmonic nanoparticles: a surface integral approach
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Recent developments in nanofabrication and optical near-field metrology have faced complementary modeling
techniques with new demands. We present a surface integral formulation that accurately describes the extreme
near-field of a plasmonic nanoparticle in addition to its far-field properties. Flexible surface meshing gives precise
control over even complex geometries allowing investigation of the effects of fabrication accuracy and material
homogeneity on a particle's optical response. Using this technique, the influence of a particle's symmetry and
shape on surrounding "hot spots" of extremely large field enhancement is explored, giving insight into the
mechanisms of surface enhanced Raman scattering and single-molecule detection techniques.
Defect state dampening of surface plasmons in Au-YSZ nanocomposites
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The optical signature of Au nanoparticles within an yttria-stabilized zirconia matrix has been demonstrated as an optical
beacon for changes in emission gas concentrations within harsh environments. It has been proposed that this broadening
in the localized surface plasmon resonance (LSPR) band is due to the inelastic scattering of plasmons by filled oxygen
ion vacancies. Using the theoretical expressions developed by others for adsorbate induced dampening, a model has
been developed for plasmonic nanocomposites to describe the changes observed in the LSPR band broadening for
metallic nanoparticles due to the same scattering mechanisms. The model agrees with the broadening observed for the
experimental results.
Plasmonic Metamaterials I
Optical activity in metal and dielectric planar chiral gratings
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When a linearly polarized light wave propagates in a chiral medium, the polarization plane azimuth rotates
clockwise or counter-clockwise depending on the handedness of the material. This effect is called optical activity.
It can be observed in a number of crystals and organic liquids, however the rotatory power of chiral materials
available in nature is useally very small. That is why chiral planar micro- or nano-structures, which possess a
much stronger rotatory power than natural chrial media, have attracted a considerable attention in recent years.
We demonstrate large optical activity of chiral subwavelength gratings having no in-plane mirror symmetry and
fabricated with metal thin films. For zeroth-order transmitted light, the chirality of these gratings manifests itself
in the non-coplanarity of the electric field vectors at the air- and substrate-sides of the metal layer and can be
interpreted in terms of the surface pllasmon enhanced non-local
light-matter interaction. We demonstrate also
that in all-dielectric subwavelength chiral gratings, the optical activity can be enhanced even stronger by using
waveguide resonance. In the terahertz (THz) region, we obtain rotation of the polarization zimuth of a linearly
polarized THz wave by using double-layered metal chiral structure with complimentary patterns.
Plasmonic Metamaterials II
Manipulating the optical transparency of anisotropic metamaterials with magnetic field and liquid crystals: influence of the nanostructures shape
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The light transmission through metallic films with different types of nano-structures was studied both theoretically
and experimentally. It is shown, analytically, numerically and experimentally, that the positions of the
surface plasmon resonances depend on nano-structural details. This leads to a strong dependence of the amplitude
of the light transmission, as well as the polarization of the transmitted light and other optical properties, on
those details. Two complementary situations are considered: a metal film with dielectric holes and a dielectric
film with metallic islands. Two different possibilities for manipulating the light transmission are considered: One
is based upon application of a static magnetic field (actually, this is equivalent to changing the nano-structure
in a transformed configuration space), the other is based upon using liquid crystals as one of the constituents of
a nano-structured film.
Experimental investigation of Fang's Ag superlens suitable for integration
Show abstract
We report on experimental realization of the Fang Ag superlens structure [1] suitable for further processing and
integration in bio-chips by replacing PMMA with a highly chemical resistant cyclo-olefin copolymer, mr-I T85 (Micro
Resist Technology, Berlin, Germany). The superlens was able to resolve 80 nm half-pitch gratings when operating at a
free space wavelength of 365 nm.
Fang et al. used PMMA since it enables the presence of surface plasmons at the PMMA/Ag interface at 365 nm and
because it planarizes the quartz/chrome mask. If the superlens is to be integrated into a device where further processing
is needed involving various organic polar solvents, PMMA cannot be used. We propose to use mr-I T85, which is highly
chemically resistant to acids and polar solvents.
Our superlens stack consists of a quartz/chrome grating mask, a 40 nm layer of mr-I T85, 35 nm Ag, and finally 70 nm
of the negative photoresist mr-UVL 6000 (Micro Resist). A 50 nm layer of aluminium on top of the quartz/chrome mask
reflected all light that did not penetrate through the mask openings thereby reducing waveguiding in the top resist layer.
The exposures took place in a UV-aligner at 365 nm corresponding to the excitation wavelength of the surface plasmons
at the mr-I T85/Ag interface. Supporting COMSOL simulations illustrate the field intensity distribution inside the resist
as well as the presence of surface plasmons at the mr-I T85/Ag boundary. AFM scans of the exposed structure revealed
80 nm gratings.
Loss monitoring in resonant photon tunneling through metal and dielectric multi-layer metamaterials
Show abstract
Loss is a critical parameter in metamaterials because it determines the resolution of a super-lens made of metamaterials.
The super-lensing effect observed in alternative multi-layer metamaterials consisting of metal and
dielectric layers is derived from the resonant photon tunneling (RPT) via surface plasmon polaritons (SPPs).
Here we demonstrates that the losses in the metamaterials can be estimated by simultaneous measurements of
attenuated total reflection (ATR) and RPT. RPT through silver (Ag)/SiO2 metamaterials is studied experimentally.
A shift of the RPT peak away from the ATR dip is observed; the shift variation in an Ag/SiO2 system is
smaller than that in an aluminum/MgF2 system. This indicates that the shift is caused by the imaginary part
of permittivity, i.e., intrinsic losses, of metamaterials.
Plasmonic Metamaterials III
Magnetic resonance in stratified metal-dielectric metamaterials
Show abstract
Effective magnetic permeability is investigated theoretically as well as experimentally for stratified metal dielectric
metamaterial consisting of alumina (60nm) /Ag (30nm) /alumina (60nm) unit cells. The permeability calculated from
complex transmission and reflection coefficients with the transfer matrix amounts to 20 just below the first photonic
bandgap. Measurements with a Mach-Zehnder interferometer were found to be consistent with theoretical prediction.
Diversity of optical indices in stratified metal-dielectric metamaterials
Show abstract
As a typical uniaxial media, stratified metal-dielectric metamaterials (SMDMs) are addressed in my talk. SMDMs have diverse features: (I) Coexistence of metallic and transparent dielectric properties in SMDMs. (II) Nearly zero refractive index just above the effective plasma frequency of metallic components. This feature has enabled to design the ultracompact wave plates. (III) In case of the small ratio of metal, the transmission windows emerge which are often connected to the optical magnetism. In some particular cases, negative refractive index is also found. (IV) When the metal part is dominant, SMDMs can have the very large refractive index.
Nanoplasmonic Applications I
Effect of surrounding medium on the optical properties of a two layer silver film
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The effect of surrounding medium on the optical properties of a two layer silver film are
investigated using an analytical model. We varied the media before the first layer, between
the two layers, and after the second layer. We find that the optical properties of the film is
dominantly determined by the medium between the two layers. The resonance wavelength
red shifts when the medium between the two layers is changed from vacuum to water and
then glass. The media before the first layer and after the second layer have little effect on the
spectra of the film when the thicknesses of the layers are larger than 40 nm.
Quantitative amplification of surface enhanced Raman scattering through plasmonic coupling in controlled nanoparticle assemblies
Show abstract
Metal nanoparticle assemblies of well-defined structure are investigated as substrates for quantitative surface enhanced
Raman scattering (SERS). The ~100 nm structures are formed from oligonucleotide-functionalized gold core and
satellite particles. Raman scattering from Cy5 incorporated on the core particles is detected before and after formation of
the coupled plasmonic structures. The amplification of Raman scattering observed upon formation of the coupled
structures matches quantitatively the increase in the fourth power of the surface E-field associated with coupling
between particles. Raman scattering per core-satellite structure is determined by calibrating measured intensities using
methanol as an intensity standard. The number of molecules that contribute significantly to the Raman signal and the
mean cross section per adsorbed molecule is determined by analysis of the spatial non-uniformity of the core surface
field distribution. Comparison of the wavelength dependence of the near field and the scattering spectrum using
simulation reveals that the wavelengths of the maxima in near and far fields are more closely aligned for the coupled
structures than for isolated cores.
Transmission through Kerr media barriers within waveguides and circuits
Show abstract
The transmission properties of a barrier composed of Kerr nonlinear media contained within a photonic crystal
waveguide or within circuits formed of photonic crystal waveguides is studied theoretically. The photonic crystal is a
two-dimensional array of linear media dielectric cylinders, waveguides are formed in the photonic crystal by replacing a
row of photonic crystal cylinders with linear media replacement dielectric cylinders, and the barrier is formed by
replacing a finite number of waveguide cylinders with cylinders containing Kerr nonlinear dielectric media. The
transmission maxima of the circuits, for an incident waveguide mode into the circuits, are determined as functions of two
parameters characterizing the Kerr nonlinear media in the barrier. The resulting two-dimensional plot in the Kerr
parameter space gives a complex pattern with features that are identified with Fabry-Perot excitations, intrinsic localized
modes, and dark soliton modes resonantly excited within the barrier. Circuits treated are straight waveguides,
waveguides with bends, and waveguides with side couplings. The theory is based on a difference equation approach
developed for nonlinear barriers in Phys Rev B 69, 235105(2004) and Phys Rev B 77, 115105(2008).
Nanoplasmonic Applications II
Sensoric applications based on plasmonic effects at metal nanoparticles
Show abstract
Localized surface plasmons (LSPs) are charge density oscillations caused by an interaction of the external
electromagnetic waves with the interface between metallic nanostructures (e.g. noble metal nanoparticles) and a
dielectric medium. Intensity and frequency of the resulting SP absorption bands are characteristic for the type of material
and depends on the size, shape and surrounding environments of the nanostructures. We have designed core/shellnanostructures
with a defined Au-core and increasing Ag-shell thickness as previously described [17]. We have used
AFM measurement and dark-field microscopy to characterize the nanoparticles, which were immobilized via silane
chemistry on glass substrates. The plasmon band of selected particles was investigated by single particle spectroscopy
(SPS) in transmission and reflection mode. Their potential as optical biosensor was demonstrated by immobilization of a
protein and a protein specific antibody leading to a refractive index change in the local environment of metal
nanoparticles, which causes a characteristic shift of the SP absorption band maximum.
Nanoplasmonic resonance energy transfer spectroscopic pH imaging
Show abstract
Nano plasmonic resonance energy transfer (PRET) spectroscopy is a new sensing technique to study the electronic
energy transfer between plasmonic nanoparticles and adsorbed biological/chemical molecules. PRET spectroscopy has
been used to detect complex biomolecular activities including conformational change, electron transfer and protein
interactions with ultrahigh sensitivity and specificity. Here we demonstrate in vitro and intracellular imaging of pH
values using PRET spectroscopy. Potentially submicron spatial resolution and decimal pH sensitivity can be achieved in
PRET pH imaging.
Poster Session
Fast surface plasmon-polariton-based optical phase modulator
Show abstract
There exists a growing need for fast spatial optical phase modulators in various applications including laser
communication for both terrestrial and ground-to-space communications, ultrafast laser pulse shaping as well as in
medical imaging. The two principal phase spatial light modulator technologies currently available namely, liquid crystal
and digital micro-mirror are limited to frame rates of a few kHz. A need therefore exists for faster MHz-range spatial
phase modulating devices. Existing solid state electro-optical modulators such as based on LiNbO3 crystal, although
capable of GHz rate modulation rates, cannot be used for 2-D spatial light modulation. This is due to their relatively
small electro-optical coefficient which requires the use of a relatively thick layer and its associated large, (100's of Volt)
modulating signal, thereby barring their practical use as spatial light or phase modulators. Surface plasmon polariton
resonances which can be excited at the metal-dielectric interfaces have been shown to significantly affect both the
amplitude and the phase of the traversing optical beam. In this work we present a preliminary study of metallic nanoparticles
embedded in a solid state electro-optical modulator (EOM), as potential spatial phase modulating device. Here,
the spatial refractive index modulation of the EOM, allows, the modulation of either amplitude of phase modulation,
with the added advantage of potentially ultra-fast frame rates. The results of computer simulations, based on finite
difference time domain (FDTD) method, with various nano-particle geometries are reported, describing the achievable
phase modulation along with the associated absorption losses.
Problem of x-ray synchrotron beam collimation by zone plate
Show abstract
We present the first results of collimating the synchrotron radiation beam by zone plate located at the long distance from
the source. Zone plate (ZP) has been fabricated from silicon crystal. We observe the interference fringes due to existence
of various orders of focusing. We record experimentally an amplification of synchrotron beam intensity up to four times
by means of ZP. The experimental measurements have been performed at the beam line BM-5 of the European
Synchrotron Radiation Facility (ESRF) for the energy interval from 8 to 17.5 keV. The fringes were discussed on the
base of analytical theory as well as were studied by means of computer simulation. The radial distribution of intensity is
determined as a convolution of the zone plate transmission function and the Kirchhoff propagator in paraxial
approximation.