This PDF file contains the front matter associated with SPIE Proceedings Volume 7781, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

In this work, we report results of lead sulfide (PbS) quantum dots (QDs) luminescence spectra evolution during the QDs spread process around the core of silica microstructured optical fibers (MOFs). These QDs are excited, via evanescent field effect, with a 532nm or 785nm laser guided by the MOF cores. The PbS-core QDs of different sizes (originally immersed in Toluene) with emission bands around 877 nm (PbS877), 1160 nm (PbS1160) and 1474 nm (PbS1474) were inserted inside the silica MOF structure by using an N2 gas pressure system. The broadband luminescence spectra varying from around 1000 nm to 1600 nm were obtained by using QDs mixtures spread around MOF core surfaces. This QDs spread technique and the PbS QDs broadband luminescence spectra results could have potential applications in optical amplifier,sensor and nonlinear optical fiber loop mirror devices.

In this paper all the key parameters i.e. V-Number, effective refractive index of the cladding, radius of the core, numerical aperture, mode field diameter (MFD) and mode field area have been obtained by Far-Field intensity pattern of endlessly single mode Photonic Crystal Fiber (ESM-PCF). The transmission characteristics of PCF are also analyzed and simulated using Improved Effective Index Method (IEIM). Results obtained from Far-field technique and IEIM are compared and found in good agreement. Hence, IEIM is experimentally supported by the far field technique.

A low-loss low-velocity photonic crystal (PhC) waveguide having rectangular air holes in-filled with a liquid crystal in Si core is proposed. The possible propagation losses due to inefficient coupling are also investigated for proposed structure. It is found that high transmission is obtained for a broad bandwidth from the output of the finally designed heterogeneous waveguide consisting of a slow liquid crystal infiltrated PhC waveguide surrounded by fast PhC waveguides on both sides.

A new design of superior gain assisted double-negative plasmonic nanoantenna to demonstrate nonlinear effects in UV/visible region. Demonstration of near-field transmission spectrum reveals the production of the local-field enhancement up to 10² for half wavelength generation with the incident light wavelength in double nanorod-antenna (DNRA) system and UV/ white light super-continuum generation for the nanoantenna array (NA) system. Negative real values of both permeability (μ) and permittivity (ε) with extremely low imaginary values for visible light is obtained by applying coupled dipole approximation. Near-field and far-field resonance spectrums reveal light amplification and high directionality for the designed nano-antenna.

A retro-reflection, polymer fiber cross section is fabricated using a tri-component fiber extruder. The fiber cross section is comprised of a series of right angles. The right angles are retro-reflection features that run the entire length of the fiber. The retro-reflective features are formed by an extrusion process where the polymer fiber material is forced through a series of plates resulting in the cross section having the desired shape. Because the fiber cross sectional features form naturally by intersecting chords, the features scale naturally and have a tendency to maintain their form when the fiber is drawn to the desired diameter. Alternating the indices of refraction of the cross-sectional features allows for the realization of a number of unique and useful optical effects. The fiber cross section exhibits refraction and diffraction qualities as well as retro-reflection properties. As such, it exhibits prismatic and multiple-order diffraction interference. Hence, the fiber appears colorful when illuminated with white light. The colors can be controlled by a number of means: for example by the inclusion of dyes, nanoparticles, and by post-processing applications of thin films.

Tantalum pentoxide ( Ta₂O₅ ) planar waveguides have recently been shown to possess unusually large nonlinearities, and nonlinear Kerr coefficient (n₂), leading to potential applications in nonlinear integrated optics, such as supercontinuum generation. In this paper, we report the experimental demonstration of a third-order susceptibility (χ⁽³⁾) governed nonlinear optical parametric process within a 7 mm long planar tantalum pentoxide waveguide using a pump-probe configuration. When pumped at 800 nm, and seeded in the near infra-red (IR) the waveguides allow parametric conversion giving rise to signal photons in the visible spectrum. By seeding the parametric conversion process in the 1200 to 1600 nm IR telecoms range, we obtain continuously tunable output over the visible range (533 to 600 nm) from a single guide.

Frequency conversion is considered as a key functionality for wavelength division multiplexing systems, which converts an incoming optical carrier of one frequency to an outgoing optical carrier of another frequency while preserving the quality of carried data. The all-optical approach is promising for such a purpose because not only the system complexity and power consumption of frequency converters are greatly reduced but also the flexibility and reconfigurability are highly improved. Four-wave mixing of solitary semiconductor lasers has been proposed to achieve all-optical frequency conversion. Although the conversion efficiency is relatively high, however, the conversion bandwidth is small, limiting the conversion range, and the efficiency flatness is poor, distorting the data signal. In this study, we propose to use four-wave mixing of injection-locked semiconductor lasers instead. When a semiconductor laser is subject to a strong optical injection, it can enter into stable locking dynamics before undergoing Hopf bifurcation. An incoming optical carrier of one frequency perturbs the injection-locked laser, generating an outgoing optical carrier of another frequency through four-wave mixing. Tens to hundreds of gigahertz of frequency conversion can be achieved, increasing the conversion bandwidth by 3 folds. The conversion efficiency varies within 5 dB over the enhanced bandwidth, improving the efficiency flatness by at least 10 dB. Greatly improved eye-diagrams and bit-error ratios are thus obtained. The input power dynamic range of the incoming optical carrier is greatly enhanced, increasing the flexibility of the proposed system.

The unusual thermophysical properties (high melt viscosity, large latent heat of fusion, fairly large equilibrium segregation coefficient, etc.) cause considerable difficulty in maintaining uniform zinc composition in the CdZnTe grown crystals. However, industrial applications still require larger high structural quality and homogeneous single crystals with a very low dislocation density, no grains nor twins. These improvements are facilitated by dewetting phenomenon in which the crystal is grown detached from the ampoule wall by a liquid free surface at the level of the solid-liquid interface, called liquid meniscus, which creates a gap between the grown crystal and the ampoule wall. In order to evaluate numerically Zn distribution in CdZnTe crystals grown by dewetted Bridgman technique using a pyrolitic boron nitride (pBN)-coated quartz ampoule, a pseudo quasi-steady state model is considered. The coupled incompressible Navier-Stokes in Boussinesq approximation, convection-conduction and conservative convectiondiffusion equations are solved by finite element technique through COMSOL Multiphysics software in the framework of a 2D axisymmetric geometry. Due to the existence of the free surface (meniscus), the Marangoni effect is considered and for its implementation the weak form of the boundary application mode is employed. The effect of the dewetting phenomenon on the zinc distribution is discussed and compared with data reported for crystals grown by classical Bridgman technique.

The unique properties of one-dimensional (1D) Fibonacci chains of dielectric layers are experimentally demonstrated and exploited for the design of new mirrors with multiple reflection spectral windows. The new mirror structures are simple, straightforward to make and enable a wide variety of multiple spectral window device performance to be achieved. By changing the thickness of the layers or the order of the Fibonacci chain, tens or even hundreds of windows can be obtained with the same approximate reflectivity over a very broad spectral region. These mirrors have numerous applications in photonics and optoelectronics.

In this paper, we have reviewed our recent works on IR supercontinuum generation (SCG) and its applications. First, we provide a brief review on the physical mechanism of the supercontinuum generation. Second, the advance of SCG in single crystal sapphire fibers is reviewed and introduced. In particular, we discussed how to fabricate thinned sapphire fiber and use it for high efficiency SCG. Finally, experimental results of chemical analysis with supercontinuum source are reviewed.

When the two-photon absorption of a high intensity pump beam takes place in a semiconductor optical amplifier there is an associated fast phase change of a weak probe signal. A scheme to realize fast all-optical NAND logic function using two-photon absorption induced phase change has been analyzed. NAND gate is important because other Boolean logic elements and circuits can be demonstrated using NAND gates as a basic building block. Rate equations for semiconductor optical amplifiers (for input data signals with high intensity) configured in the form of a Mach-Zehnder interferometer has been solved. The input intensities are high enough so that the two-photon induced phase change is larger than the regular gain induced phase change. The model shows that both AND and NAND operation at 250 Gb/s with good signal to noise ratio is feasible.

A new simplified structure of highly birefringent chalcogenide As₂Se₃ glass Photonic Crystal Fiber (PCF) with low confinement loss is designed and analyzed by using fully-vectorial finite element method. The effective indices, confinement losses, birefringence and chromatic dispersion of fundamental polarized mode are calculated in the proposed PCF. It is also shown that As₂Se₃ glass PCF provides lower chromatic dispersion and less confinement loss compared to silica PCF of the same structure and hence such chalcogenide As2Se3 glass PCF have high potential to be used in dispersion compensating and birefringence application in optical communication systems.

Solid-state photomultipliers (SSPM) are photodetectors composed of avalanche photodiode pixel arrays operating in Geiger mode (biased above diode breakdown voltage). They are built using CMOS technology and can be used in a variety of applications in high energy and nuclear physics, medical imaging and homeland security related areas. The high gain and low cost associated with the SSPM makes it an attractive alternative to existing photodetectors such as the photomultiplier tube (PMT). The capability of integrating CMOS on-chip readout circuitry on the same substrate as the SSPM also provides a compact and low-power-consumption solution to photodetector applications with stringent area and power requirements. The optical performance of the SSPM, specifically the detection and quantum efficiencies, can depend on the geometry and the doping profile associated with each photodiode pixel. The noise associated with the SSPM not only includes dark noise from each pixel, but also consists of excess noise terms due to after pulsing and inter-pixel cross talk. The magnitude of the excess noise terms can depend on biasing conditions, temperature, as well as pixel and inter-pixel dimensions. We present the optical and noise performance of SSPMs fabricated in a conventional CMOS process, and demonstrate the dependence of the SSPM performance on pixel/inter-pixel geometry, doping profile, temperature, as well as bias conditions. The continuing development of CMOS SSPM technology demonstrated here shows that low cost and high performance solid state photodetectors are viable solutions for many existing and future optical detection applications.

Single beam dynamic holographic recording is realized in the photorefractive crystals. Different photorefractive mechanisms of holographic recording are discussed. Feasibility of single beam holographic interferometry with the transparent and opaque objects (like oil and water droplets) in transmission and reflection is demonstrated.

Fabrication of single-mode fiber coupler has widely expands. However, directional fiber coupler geometry always affects the power propagation either two or three ports. This paper describes power launching by NX3 single mode fiber, examined using a matrix transfer for linear and triangle order, calculated from the eigenvalue and the eigenvector. This eigenvalue is referred to the coupling coefficient, where it can be expressed as an effective power transmitted to another fiber. The ratio of coupling coefficient between adjacent axial fibers varies, which can be achieved by adjusting separation of fiber and refractive index of core and cladding. A calculation has been shown in 3D that both power transmission and phase are affected by not only the geometry order, but also the variation of coupling coefficient, assuming the propagation constants, cross section, and separation of coupling length fiber axis are held constant. This calculation can be applied for any sources of wavelength and junction.

We propose a new method for mass production of the photonic crystal devices on the basis of widely-known and well-developed technology such as micristructured optical fibers. In this paper, we investigate the optical properties of side-excited microstructured fiber and discuss the conditions for utilization such a structure as planar photonic crystal device, namely, the high-quality resonance filter.

The fabrication of small-core photonic crystal fibers and preliminary supercontinuum generation characterization are reported. In such non-linear experiments fs pulses from a Ti:Sapphire laser were coupled in the fiber core and the generated spectra recorded.

We present a method to make liquid lenses. It is based on the microfluidic method to make emulsions. An emulsion is a mixture of two immiscible liquids, where one liquid (the dispersed phase) is dispersed in the form of small droplets in another liquid that forms a continuous phase. The presence of a surfactant is necessary for the long term stability of emulsions. To make liquid lenses we have used capillaries. Through them we inject some microliters of a liquid. The result is that a spherical micro-lens is formed. These lenses can focus light or form images. We have tested the lenses through image forming techniques and compared the results with the ones given by an optical design program.

An algorithm using fringe projection to retrieve the 3D shape from images blurred by motion is described. Theoretical analysis shows that objects moving within one period of the projected fringe can be directly described by the projected fringe profilometry. Thus, the cost of the detection system is effectively reduced.

An algorithm using fringe projection to perform the speed measurement is described. A fringe pattern is illuminated onto the dynamic object, and a CCD camera is used to record the fringe distribution. Fringes on the obtained image are deformed by the topography of the object, and also, blurred by motion. Thus, the blurred fringes supply additional information to describe the speed of motion. Only one shot measurement is required for data processing. This makes it possible to perform the speed measurements with low environmental vulnerability.

A database system based on the empirical mode decomposition (EMD) to automatically reduce the subjective speckles in a fringe pattern is presented. To accurately evaluate the performance of speckle-reduction by the EMD, a method to design a computer generated signal is proposed as well. The simulation showed that the number to removed IMFs is changed when the period of the computer generated signal or the signal-to-noise ratio varies. Thus, we built up a database to identify the required number of removed IMFs. With reference to the database, speckles on the fringe pattern can be efficiently and robotically reduced.

An approach using a phase mask to enlarge the depth measuring range for a 3D shape sensing system is presented. A microscope combined with a wide-angle eyepiece lens is employed to project a fringe pattern onto the inspected surface. A CCD camera observes the projected fringes through another microscope with a phase mask. The phase mask enlarges the depth of field of the image acquisition system, while the wide-angle eyepiece lens increases the depth of focus of the fringe projection system. It is found that the depth measuring range has been extended up to 1600-micron, even though the depth of field of the image acquisition system is only 80-micron.

We present sensing characteristics of higher order rocking filters fabricated in highly birefringent microstructured fiber which resonantly couple polarization modes at several wavelengths. First rocking filter (RF1) shows tree resonances arising at 855, 1271, and 1623 nm, while in the second filter (RF2) the resonances arise at 908, 1145, 1354 and 1548 nm. We measured sensitivity to temperature in both filters and to hydrostatic pressure in the RF1. Our results show that both filters have very low response to temperature ranging from 1.38 to 3.03 pm/K depending on the resonance order. Simultaneously, the sensitivity to hydrostatic pressure is very high and reaches 6.14 and 3.30 nm/MPa, respectively for the first and the second resonance in the RF1. These unique sensitivity characteristics make the filters an excellent device for hydrostatic pressure measurement with no need for temperature compensation.

Heat transfer has the important influence in quantum effect of light emitting diode (LED). In the industrial processing, the quality of the thermal dissipation decides by the gumming technique between the printed circuit board (PCB) and aluminum plate. Because it transfers the heat from electric device to the aluminum plate which removes the heat. In this work, the alumina nitride (AlN) thin film soldered the LED lamps to enhance the heat transfer. The films were fabricated onto 1070 aluminum substrate by vacuum sputtering and plasma spraying technologies individually. The dielectric coatings were characterized by several subsequent analyses, especially the real temperature measurement of dielectric coating films. The X-Ray diffraction (XRD) diagram analysis reveals that ceramic phase can successfully grow on the individual substrate. The studied results show that AlN thin film fabricated by vacuum sputtering has low sheet resistivity, high hardness, high critical load, and good thermal conduction (200 W/m-K); but, the same of coating fabricated by plasma spraying technology had the best heat transfer as compared to the other samples.

The thermal conductivity has the important influence in quantum effect of light emitting diodes (LED) especially in high brightness light emitting diodes (HB LED). One of the biggest challenges is efficient heat transfer from PCB to aluminum plate when it base on printed circuit board (PCB). Because it enables transfer the heat from electric device to the aluminum plate, which completely removes the heat. In this study, alumina (Al₂O₃), alumina nitride (AlN) and zinc sulfide (ZnS) films soldered the HB LED lamps to enhance the heat transfer. All of the films were fabricated onto 1070 aluminum substrate by vacuum sputtering technology. The dielectric coatings were characterized by several subsequent analyses, especially the measurement of thermal resistance. The X-Ray diffraction (XRD) diagram analysis reveals three kinds of ceramic thin films were successfully grown on the individual substrate. Moreover, the alumina nitride coating has low sheet resistivity, high hardness, high critical load, and good thermal conduction, 200 W/m-K, as compared to those of Al₂O₃ and ZnS films.

Photoresponsive polymers undergo structural changes (expansion or contraction) upon photoirradiation[1]. This group of polymers when polymerized with arrays of colloidal particles self-assembled into a crystalline colloidal array (CCA) forming a polymerized CCA (PCCA). The functionality of the CCA is enhanced by polymerizing it, due to the inclusion of specific properties of the polymer. Combining the properties of both, significant change in the lattice size is observed under external stimuli resulting in an optical response of the PCCA (either a blue or red shift of the spectrum)[2],[3]. Novel tunable nanophotonic devices that enable a camouflage behavior could be realized using this technique. Camouflage behavior is achieved when an object blends into the environment, making it indiscernible from its surroundings. One approach to achieving such behavior in an object is to reflect only the wavelength that is predominant in the range of wavelengths incident from its surroundings. In this work we model and simulate a 3D polymerized photonic crystal structure which has the potential to exhibit this behavior. Simulations are performed to model the dynamic band gap tuning of the 3-D photonic crystal using the MIT Photonic Bands (MPB) and OptiFDTD optical modeling tools. These results lend a key understanding to the design of PhC's that exhibit dynamic band gap tuning, and how they can be applied in device designs.

A novel type of electro-optic scanner is presented which can satisfy the requirements for high speed and large-angle. It is a two-stage cascade system which consists of a fine scanning system implemented by using voltage-controlled refraction-based electro-optic deflectors and a coarse scanning using several LiNbO₃ electro-optic switch and polarization beam splitter system. The deflection angle can be enlarged by using the coarse-fine cascaded system. We demonstrate the design scheme of the proposed large-angle optical beam scanner. The system is analyzed and simulated theoretically. It is shown that proper design of the parameters of coarse-fine cascaded two-stage system can lead to an optimal beam scanner with enhanced performance of large angle and high speed. The analysis and observations will be valuable for the accurate design and fabrication of the novel optical scanning devices based on electro-optic effect.

The laser-induced domain nucleation effect is investigated in the 3mol% hafnium-doped congruent lithium niobate crystal. The beam from an Ar-ion laser with 514 nm wavelength is focused on z surface. Two incidence schemes are performed: (1) irradiating near and focusing on the +z surface; (2) irradiating near and focusing on the -z surface. The formed space charge field is observed by the in-situ phase mapping during the laser-induced domain nucleation. The variations of phase distributions are reconstructed by the digital holographic interferometry. The light intensity dependence of the measured photovoltaic current density j^phv is described. The space charge field along -z direction is thought to be an important mechanism for the laser-induced domain nucleation. According to these experimental results, we present a qualitative model on the laser-induced domain nucleation process in lithium niobate crystal.

Two-wave coupling in LiNbO₃:Fe:Ru crystals is investigated experimentally and theoretically in this paper. The dependence of gain coefficient on doped concentration, as well as the light intensity ratio between pump beam and signal is experimentally investigated, the maximal gain coefficient 9.2cm^-1 is found while the ratio is 2.2, light gain cannot be observed in the reduced sample because of fan effect. Effect of phase difference between light modulation and the refractive index grating on two-wave coupling is investigated based on jointly solving the two-center material equations and the coupled wave equations, the variation of phase difference is obvious in the crystals with reduced process or high doped concentration.

Photonic fiber with single mode couplers or splitters at each fiber end can be used as a sensitive structure for fiber sensing applications. The sensitive structure is created with two DFB lasers at λ = 1550 nm. Each laser is connected to opposite sides of photonic fiber provided with SM couplers. One DFB laser is isolated and its light goes through variable attenuation. Isolation is necessary for DFB laser stability. The second laser is DFB or F-P laser without any isolator. Its radiation is driven as with driven current so with DFB laser passing through photonic fiber. Small changes of DFB laser light passing through photonic fiber activate large changes in FP laser radiation. Temperature and pressure actuating on photonic fiber are examples of effects that are able to change properties of passing laser light. These changes can be measured with the help of photo detector at the second arm of SM couplers. Changes in optical spectra of F-P and DFB laser under temperature and pressure are the results.

Characteristic of electro-optic modulation of light propagating near the optic axis in a uniaxial crystal is well known but not for the cases of propagating bias the optic axis. In this paper, two pairs of LiNbO₃ crystal plates with the same sizes consist of an optical system in where the sum of geometrically optical length of o-ray and e-ray is equal. And then the characteristics of electro-optic modulation of light propagating bias the optic axis in LiNbO₃ are studied experimentally through a coherent received system. The additional phase shift caused by electro-optic effect is measured. The relation of phase shift varying with applied electric-field is reported when the angle between incident beam and the optic axis is 45°. Based on above experiments, a new 90º optical hybrid will be developed.

In this paper we describe photo-induced trapping/redistribution of silver nano-(micro) particles near the surface of photorefractive crystal LiNbO₃:Fe. This type of optical trapping is due to combined forces of direct gradient-force trapping and asymmetric photorefractive forces of electro-phoresis and dielectro-phoresis. The silver nanoparticles were produced through extracellular biosynthesis on exposure to the fungus, Fusarium oxysporum (FO) and to the plant extracts. Pulsed and CW visible laser radiation lead to significant modification of nanoparticle clusters. This study indicates that extracellular biosynthesis can constitute a possible viable alternative method for the production of nanoparticles. In addition, the theoretical modeling of asymmetric photorefractive electric field grating has been presented and compared with the experimental results.

A numerical analysis of the fiber-optic surface plasmon resonance (SPR) sensor with crescent shape of metal coating is presented. The crescent shape of metal coating usually occurs during one side metal deposition on the cylindrical fiber. Here, for analysis of the performance of fiber-optic SPR sensors with such asymmetric metal coating, the method of three-dimensional (3D) ray-tracing and theoretical calculation of electromagnetic reflection and transmission at the metal film are applied simultaneously, which result in 3D analysis with reduced time consumption and data loads. We investigate the characteristic of fiber-optic SPR sensor with asymmetric metal layer, comparing with those of the symmetric metal coated fiber, and discuss the asymmetry effect of the sensors for practical sensing and provide the information for improving sensing capability.

In this paper, we present the design and the fabrication method for high DC bias voltage photoconductive semiconductor switch (PCSS). By employing a low temperature grown molecular beam epitaxial GaAs (LT-MBE GaAs) and a proper protection coating to prevent air breakdown, the DC bias electric field can be significantly increased. Such a PCSS structure can effectively achieve a low DC dark current in a high voltage pulse generation system with smaller PCSS sizes. DC bias capability also eliminates the need of complicated synchronization. The application of high DC bias field PCSS will also be discussed.

Microwave assisted synthesis of crystalline FeBO₃ powder is investigated in a multimode cavity at 2.45GHz as a possible method for faster synthesis. An Alumina-SiC susceptor enclosure was placed inside the cavity to overcome poor microwave absorption of the precursor at low temperatures. Enhanced diffusion was observed with appropriate precursor viscosity at reaction temperature. Less than 8 hours was found enough to complete FeBO₃ synthesis, as compared with more than 20 hours of synthesis using conventional muffle oven. Microwave enhanced diffusion was not obvious with too high viscosity and eventually leveled by thermal diffusion with too low viscosity. The microwave synthesized FeBO₃ particles were found more rhombohedral and smaller than conventional furnace synthesized ones, thus are inherently more suitable as optical composite materials.

In this paper, recent works of buried chemical detection system by stimulating and enhancing spectroscopic signatures with multi-frequency excitations are discussed. In this detection system, those multiple excitations, including DC electric field, microwave, CO₂ laser illumination and infrared radiation, are utilized and each of them plays a unique role. The Microwave could effectively increase the buried chemicals' evaporation rate from the source. The gradient DC electric field, generated by a Van De Graaff generator, not only serves as a vapor accelerator for efficiently expediting the transportation process of the vapor release from the buried chemicals, but also acts as a vapor concentrator for increasing the chemical concentrations in the detection area, which enables the trace level chemical detection. Similarly, CO₂ laser illumination, which behaves as another type vapor accelerator, could also help to release the vapors adsorbed on the soil surface to the air rapidly. Finally, the stimulated and enhanced vapors released into the air are detected by the infrared (IR) spectroscopic fingerprints. Our theoretical and experimental results demonstrate that more than 20-fold increase of detection signal can be achieved by using those proposed technology.

A novel two channel multi-frequencies division multiplexed confocal fluorescence microscopy (FDMCF) system based on the holographic polymer dispersed liquid crystal (H-PDLC) optical chopper modulation is reported. The characteristic of unique FDMCF system is that within the FDMCF system, the multi-channel exciter laser beams are modulated with different carrying frequencies, after the fluorescence signals are collected, and through data analyzing process, the FDMCF system can realize the multiply points parallel detection synchronously with high temporal and spatial resolution. Besides, combined with the electrically controlled H-PDLC grating array working as the optical chopper to replace the mechanical chopper, it can improve and develop the FDMCF system from two channels to unlimited system. The paper has done the experiments to demonstrate the two-channel FDMCF system based on H-PDLC modulation and analysis the benefits from the electrically-controlled integrated electro-optical H-PDLC devices.

Zinc oxide (ZnO) nano-wires have draw people's attention in recent studies. The unique structural and physical properties offer fascinating potential for future technological applications. The state-of-the-art fabrication process of ZnO nano-wires is based on vapor-liquid-solid (VLS) method. In this paper, the microwave assisted heating technique is introduced for the growth of ZnO nanopillar arrays. The microwave grown ZnO nanowires were characterized by fieldemission scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and photoluminescence spectroscopy. It was demonstrated that (001) oriented single crystal ZnO nanowires can be grown vertically and uniformly on a-plane sapphire wafers.

Very important advantage of ZnO thin films is an opportunity of use in the composite heterostructures opening opportunities for development of ZnO-based optoelectronics devices. In this work we report the preparation of ferroelectric crystal - ZnO thin film heterostructures by vacuum deposition method and creation of new type of pyroelectric photodetector. The ferroelectric field effect transistor has been prepared using ZnO:Li films as transistor channel and LiNbO3 and TGS crystals as pyroelectric sensitive element. The photoelectric properties (currents ratio, charge carriers mobility, ampere-watt sensitivity in IR diapason, NEP sensitivity, and photocurrent kinetics) of prepared heterostructures were investigated and first samples of novel pyroelectric photodetector with high sensitivity and detectability were prepared.

A doubly-doped LiNbO₃ (LN) crystal has been well used as a nonvolatile two-wavelength recording material. By using two levels of the crystal, two-kind holograms can be recorded on one crystal; a hologram is recorded with a 405-nm blue laser diode (LD) for a deep Mn level, and another hologram is with a 532-nm green laser for a shallow Fe level. The recording capacity doubles. A 780-nm LD is non-volatile reconstructing source since the LD line is insensitive to both levels. Multiplexed reconstructed images are demonstrated by using a sharp angular selectivity of a volume LN crystal keeping Bragg condition with spherical reconstructions.