偏振型空间调制干涉成像光谱技术的研究

介绍一种基于偏振原理的空间调制干涉成像光谱技术 ,对这种干涉光谱仪干涉图样的形成及其处理技术进行了理论上的分析 ,为偏振型空间调制干涉成像光谱仪的研制提供理论依据。     

宽场偏振干涉成像光谱仪的调制度研究

干涉成像光谱技术是一种集双光束干涉技术、二维成像技术以及高分辨率光谱技术于一体的高新遥感探测技术,常用来进行监视、识别和探测各种民用和军事目标。基于双折射晶体的宽场偏振型干涉成像光谱仪是该技术中的一种典型代表,组成其系统的偏光元件的性能是决定其成像质量和光谱复原精度的关键因素。论文考虑元件偏振误差和延迟误差对光路传播的影响,采用偏振追迹法推导出了系统干涉调制度的理论表达式,给出了其随入射角、入射波长、入射方位角以及元件偏振化方向和相位延迟量的变化特性,并定量分析了其允差范围。这为基于偏光器件成像光谱仪的系统设计、高光谱复原以及工程实践提供了重要的理论指导和技术支持。     

静态成像光谱偏振仪

提出了一种基于幅度调制技术和空间调制干涉成像光谱技术的静态成像光谱偏振仪(SISP).利用由消色差1/4波片、多级相位延迟器和线偏振器组成的光谱偏振调制模块将入射光的斯托克斯分量信息调制到不同的波数上,利用干涉成像光谱仪单次曝光获得经光谱偏振调制的干涉图,不同的斯托克斯分量在干涉图上分离,再采用傅里叶变换从干涉图上解调...     

偏振光谱仪偏振探测精度分析

用于野外地物偏振光谱测量的偏振光谱仪,其偏振探测精度直接影响到地物偏振光谱信息获取的准确性,进而影响到目标偏振特性的解译水平。设计了适用于光栅光谱仪的偏振测量组件,将两种型号的光栅光谱仪改装成偏振光谱仪。基于可调偏振度光源验证偏振光谱仪的偏振光谱测量精度,首先分析了偏振光谱仪的偏振敏感性,然后给出了偏振光谱仪对可调偏振度光源输出不同偏振度谱的实验测量结果。实验结果表明:在460~920 nm波长范围之间,偏振光谱仪具有一定的偏振敏感性,加装退偏器之后,偏振光谱仪对输出光的测量偏振度与可调偏振度光源输入的标准偏振度具有很好的一致性,实测值与理论值的绝对误差均在2%以内,从而验证了两种型号的偏振光谱仪偏振测量组件设计的可行性,能够满足实验测量的要求。     

基于PSIM技术的偏振光谱仪测量数据处理方法

偏振光谱强度调制（PSIM）是一种先进的偏振光谱测量技术,测量数据处理是PSIM偏振光谱仪解析待测光偏振光谱信息的关键环节。论文从PSIM技术的调制、解调机理出发,结合相关数字信号处理理论,给出了从PSIM偏振光谱仪系统的测量数据中,解析待测光四个Stokes矢量元素谱的数学原理,建立了PSIM偏振光谱仪的测量数据处理流程。搭建了PSIM偏振光谱仪实验装置,分别对平行光管直接输出光信号及平行光管加透光轴水平方向偏振片后输出的光信号进行了测量实验。利用建立的PSIM偏振光谱仪测量数据处理流程,对实验装置的测量数据进行了偏振光谱信息解析处理,处理结果与理论分析结果间良好的一致性,验证了PSIM偏振光谱仪系统数据处理方法的正确性。     

偏振干涉成像光谱仪中的格兰泰勒棱镜透射比

透射比是评价格兰泰勒棱镜性能优劣的一个重要指标,分析了偏振干涉成像光谱仪中重要偏光部件即格兰泰勒棱镜的分光机理,运用光线追迹方法,推导出了晶体光轴不平行时棱镜透射比精确理论计算公式;通过计算机模拟对其传输特性进行了详尽分析,得出了系统透射比随晶体光轴倾斜角和波长变化的关系曲线;给出了在满足系统透射比条件下格兰泰勒棱镜晶体光轴误差被限定的有效区间范围。这一结论为偏振干涉成像光谱仪的优化设计提供了理论指导和技术支持。     

机载高光通量双波段成像光谱仪的设计

分析了成像光谱仪常见结构的优缺点并给出了分析过程,对望远镜系统和光谱成像系统结构进行了合理选择,实现了单一成像光谱仪同时覆盖可见近红外(VNIR)和中波红外(MWIR)双波段。根据研究目标要求设计了一个大F数(VNIR波段F/3,MWIR波段F/2)机载双波段成像光谱仪。该光谱仪双通道共用一个同轴平场无遮挡Schwarzschild望远镜,用二向色分束器分开。双通道光谱成像系统均采用同心共轴的Dyson结构,VNIR波段和MWIR波段光谱分辨率分别达到5 nm和15 nm。为使设计的系统结构合理,介绍了光束分离结构和光谱仪的光束折叠方法。设计结果表明:该系统结构简单,效果良好,谱线弯曲分别小于1.2μm和0.5μm,谱带弯曲均小于0.5μm,偏振灵敏度小于4%,适用高光谱分辨率机载双波段成像光谱仪。     

基于偏振的红外成像目标模拟技术研究进展

随着红外成像制导武器的不断发展,红外目标模拟器的各项性能也在不断得到提高以满足仿真试验的需求。现今,红外偏振成像技术已经日趋成熟,基于红外偏振成像的探测系统及制导武器也正在研制之中。根据偏振产生和偏振调制技术,讨论了几种可为偏振成像探测系统和偏振成像制导武器提供目标偏振信息的红外偏振成像目标模拟系统。     

高分辨率成像光谱的偏振监视装置

德国柏林空间遥感仪器技术研究所和德国空间局卫星系统光学仪器部等部门合作研制成像光谱仪用的偏振监视装置。由于对地面和环境观测的光学遥感系统要求集中于辐射探测精度,特别是对高分辨率成像光谱仪对辐射精度要求越来越高。对遥感仪器精确和认真地进行地面和飞行标定是满足高精度要求的基本条件之一。根据     

全偏振态同时探测实时彩色偏振成像技术

偏振光学成像技术作为一种新型的光学成像技术,通过对光波偏振特性的探测,增加了信息的探测维度,有利于全面、准确地获取目标的信息.文中阐述了偏振成像的探测方法,典型偏振成像系统的分类;详细介绍了一种基于Stokes矢量方法的分孔径全偏振态同时探测的实时彩色偏振成像相机;利用该相机进行了全偏振度成像实验和偏振去雾成像实验.实验表明全偏振态同时探测偏振成像技术在提高成像探测距离、目标细节获取及恢复等方面具有一定优势,能够为现代光学成像探测系统提供重要的技术补充.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.