Electro—optical Properties of Liquid Crystal Composite Materials

The liquid crystal composite materials consist of microdroplers of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization.The director configuration in liquid crystal droplets.the model of orientation of droplets,and the contrast ratios of a cell are investigated.Droplet size,spacing and distribution are readily controlled in these materials to allow optimization of displays based upon electrically controlled light scattering from the liquid crystal droplets.Preliminary experimental and theoretical studies of the light scattering and electro-optic response of new material show that these materials can offer new features suitable for large area displays and light valves.     

Influence of Heat-radiating on Multi-photon Compton Scattering High-energy Electron

Using the model of the inverse Compton scattering between high-energy electrons and heatradiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied. The results show that the energy loss, power loss, light resistance and light pressure of the high-energy electron formed by heat radiating are all proportional to the temperature T^4 of the vacuum cavity of the electron,the Lorentz factor γ^2 of the high-energy electrons, the scattering section of the electron and the number of photons acting at the same time with high-energy electrons. A good method for lessening the energy loss of the high-energy electron by using the one-photon Compton scattering between high-energy electrons and heat radiation photons is proposed.     

Impact of crystal orientation and surface scattering on DG-MOSFETs in quasi-ballistic region

The characteristics of nano scale n-type double gate MOSFETs with (100) and (110) surfaces are studied using 3D full band ensemble Monte Carlo simulator.The anisotropic surface scattering mechanism is investigated.The (100) case is sensitive to the gate voltage more than the (110) case.The impact of crystal orientation and surface scattering on transport features mainly reflects in the carrier velocity distribution.The electron transport features with (100) direction are greater than that with (110) direction,but are more likely to be affected by the surface scattering.     

Electron Raman scattering in a HgS/CdS spherical quantum dot quantum well

Electron Raman scattering （ERS） is investigated in a spherical HgS/CdS quantum dot quantum well （QDQW）. The differential cross section （DCS） is calculated as a function of the scattering frequency and the sizes of QDQW. Single parabolic conduction and valence bands are assumed. The selection rules for the processes are studied. Singularities in the spectra are found and interpreted. The ERS studied here can be used to provide direct information about the electron band structure of these systems.     

NUMERICAL SIMULATIONS OF POLARIZED SCATTERING FROM RANDOM CLUSTERS OF SPATIALLY-ORENTED, NON-SPHERICAL SCATTERS

Employing multiple scattering formulation of T-matrix method, numerical simulations are developed and applied to polarized scattering from random clusters of spatially-oriented, non-spherical particles. Polarized scattering is numerically presented for the functional dependence on particle shape, size, spatial distribution and orientation, and other physical parameters. Numerical calculations of backscattering from randomly clustered particles are well compared with that from independent particles and clusters. It can be seen that spatial distribution and orientation of non-spherical particles can have significant effect on scattering.     

Scattering performance of a plane wave by conducting finite helix

The scattering of a plane wave with a linear polarization by a conducting finite helix is presented. The analytical expresses of scattering field are obtained based on the boundary condition of a sheath helix model. Effects of a pitch angle and electrical size of the helix on the resonant behavior are investigated. The analysis shows that resonant behavior of the forward/backward scattering far field is only depended on the pitch electrical size and the radial electrical size, but it is independent of the turn of the helix.     

Dynamical control of directional nonlinear scattering from metallic nanoantennas by three-dimensional focal polarization orientation

We demonstrate that the directionality of far-field second harmonic(SH) emission generated from individual gold nanosphere can be flexibly engineered by manipulating three-dimensional(3D) focal polarization orientation of the excitation field, which is explained by the coherent interference between SH dipolar and quadrupolar emission modes. The SH dipolar emission mode is independent of the polarization direction of the fundamental field whereas the evolution of the focal polarization orientation can dramatically modify the quadrupolar emission pattern. Therefore, the resultant SH emission pattern has a polarization-dependent behavior and side scattering almost perpendicular to the propagation direction of the incident light can be observed under a specific condition. Our findings provide a novel degree of freedom for all-optical control of directional nonlinear scattering from single nanoantenna, thereby opening new possibilities for future potential applications.     

Effect of γ—ray Radiation on Loss of Optical Fiber in Visible Range

The mechanism of γ-ray radiation induced absorption loss of the optical fiber in visible range is analyzed.According to the mechanism,the quantitative relation between loss in optical fiber and γ-ray cumulation dose is found by use of methods of solid physics and statistic physics.This quantitatie relation is certified in terms of the results of radiation experiment.     

Effect of γ-ray Radiation on the Loss of Optical Fiber in Visible Range

The mechanism of γ-ray radiation induced absorption loss of the optical fiber in visible range is analyzed. According to the mechanism, the quantitative relation between loss in optical fiber and γ-ray cumulation dose is found by use of methods of solid physics and statistic physics. This quantitative relation is certified in terms of the results of radiation experiment.     

Self-trapping Characteristics of Partially Coherent Optical Beam in Photonic Crystal Fiber under Compton Scattering

Using the mutually coherent function, the self-trapping of the circle partially coherent optical beam in the total internal reflective photonic crystal fiber（TIRPCF） under Compton scattering is studied. The study shows that the composition of the non-coherent optical beam in the optical spectrum and the diffraction effect are decreased by Compton scattering, and the probability of forming the soliton is greatly increased. The vibration peak value in the propagation, compressed degree, changed cycle, and radius of the soliton are all smaller than those before the scattering, but its coherent radius is larger than that before the scattering. In this propagation, the self-focusing plays a key role.     

Full Band Monte Carlo Simulation of Electron Transport in Ge with Anisotropic Scattering Process

The electron transport properties in Ge are calculated by full band Monte Carlo technique with anisotropic scattering consideration.The calculation procedures are as follows:the full band structure is calculated by nonlocal empirical pseudopotential approach;the relative value of density of state (DOS) is computed by counting the number of states located in a certain region of the energy;the phonon dispersion curve is obtained from an adiabatic bondcharge model;the electron-phonon scattering rates are approximated by the nonparabolic model derived from Fermi’s golden rule at low energy region and scaled by DOS at higher energy region;the energy and momentum conservations are employed for choosing the final state after scattering.The validity of this Monte Carlo simulator and the physical models that are used is fully confirmed by comparing the program output to experimental results listed in references.As this Monte Carlo model can accurately reproduce the velocity and energy characteristics of electrons in Ge and the DOS scaled scattering rate can significantly reduce the computational cost for scattering rates,this approach is suitable for device simulation.     

Influence of pH of spray solution on optoelectronic properties of cadmium oxide thin films

Highly conducting transparent cadmium oxide thin films were prepared by the conventional spray pyrolysis technique. The pH of the spray solution is varied by adding ammonia/hydrochloric acid. The effect of pH on the morphology, crystallinity and optoelectronic properties of these films is studied. The structural analysis showed all the films in the cubic phase. For the films with pH < 7(acidic condition), the preferred orientation is along the(111) direction and for those with pH >7(alkaline condition), the preferred orientation is along the(200) direction.A lowest resistivity of 9.9104 cm(with carrier concentration D5.11020cm3, mobility D12.4 cm2/(V s))is observed for pH12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70%. Thus, the electrical conductivity of CdO films could be easily tuned by simply varying the pH of the spray solution without compromising the optical transparency.     

Raman Scattering Spectrum Analysis of GaP and Its Luminous Materials^①②

The Raman scattering spectra of n-type GaP(doped S) single crystal and red and green luminous materials grown on the n-type GaP(doped S)single crystal substrate by liquid-phase epitaxy are analyed.The results show that the spectra of GaP single crystal and its luminous materials include not only the first-order longitudinal optical photons and transverse optical phonons Raman scattering peaks,but also the peaks of the bound excitons,bound electrons and bound holes.     

Raman Spectra of AlP／GaP Short—period Superlattice

The samples of (AlP)n/(GaP)n short-period superlattics(period number n=4,6)grown by MOVPE and the sample of n-GaP(100)single crystal substrate are measured and analyzed by Raman spectrum.In the three kinds of samples,the double-phonon modes of first-order Raman scattering peaks are all existent.Moreover,the second-order Raman scattering peaks are observed to exist.     

GeOI pMOSFETs空穴迁移率的物理模型

A physical model of hole mobility for germanium-on-insulator p MOSFETs is built by analyzing all kinds of scattering mechanisms, and a good agreement of the simulated results with the experimental data is achieved, confirming the validity of this model. The scattering mechanisms involved in this model include acoustic phonon scattering, ionized impurity scattering, surface roughness scattering, coulomb scattering and the scattering caused by Ge film thickness fluctuation. The simulated results show that the coulomb scattering from the interface charges is responsible for the hole mobility degradation in the low-field regime and the surface roughness scattering limits the hole mobility in the high-field regime. In addition, the effects of some factors, e.g. temperature, doping concentration of the channel and the thickness of Ge film, on degradation of the mobility are also discussed using the model, thus obtaining a reasonable range of the relevant parameters.     

Properties of Differential Scattering Section Based on Multi—photon Nonlinear Compton Effect

Properties of damping electrons in collision with photons based on multiphoton nonlinear Compton effect are investigated.The exressions of the differential scattering section are dervied.Several useful conclusions are drawn.     

Temperature Dependent Raman Scattering of Phonon Modes and Defect Modes in GaN and p-Type GaN Films

Raman spectra of undoped GaN and Mg-doped GaN films grown by metal-organic chemical-vapor deposition on sapphire are investigated between 78 and 573K.A peak at 247cm－1 is observed in both Raman spectra of GaN and Mg-doped GaN.It is suggested that the defect-induced scattering is origin of the mode.The electronic Raman scattering mechanism and Mgrelated local vibrational mode are excluded.Furthermore,the differences of E2 and A1(LO) modes in two samples are also discussed.The stress relaxation is observed in Mg-doped GaN.     

Photoluminescence Characterization of Boron-doped Si Layers Grown by Molecular Beam Epitaxy

Photoluminescence spectra were used to characterize the boron-doped Si layers grown by molecular beam epitaxy using HBO2 as the doping source. The influence of boron doping concentration on the dislocation-related photoluminescence spectra of molecular beam epitaxy Si layers annealed at 900 ℃ was studied with different doping concentrations and growth temperature. The broad photoluminescence band（from 0.75 eV to 0. 90 eV） including D1 and D2 bands was associated with high boron doping concentration in the samples, while D3 and D4 bands might be related to oxygen precipitates.     

Assessment of nanocomposite photonic systems with the X-ray photoelectron spectroscopy

The chemical compositions of Ag-Er co-doped phosphate and silicate glasses were investigated with X-ray photoelectron spectroscopy with the purpose to identify the chemical state of silver. The analysis of the Ag 3d core lines show the presence of nanometer-sized silver particles in each of the annealed samples,even if these Ag 3d lines appear to be very different from each other. We explain these results as a different interaction of silver with the two glasses matrix,which leads to a different nucleation rate of the Ag clusters.     

Preparation and Properties of C—axis Oriented PT／PEK—c Films

The preparation of PT/PEK-c films is reported as well as their dielectric and optical properties.The c-axis orientation ratio of the films is 68%.Dielectric constant and loss factor at 10kHz is about 4.023 F/m and 0.003, respectively.The refractive indices of the films,ne and no, are 1.6573 and 1.6278 at 0.63μm wavelength, respectively.The optical band-gap of the film with a thickness of 2.33μm is found to be 3.06eV.