噪声等效光谱辐亮度定标系统的性能测评

噪声等效光谱辐亮度（NESR）是代表红外遥感器极限探测能力的关键性指标。高灵敏红外遥感器的NESR定标需要高稳定、高均匀和充满视场的红外辐射光源,其光谱辐亮度的不确定度应当显著低于红外遥感器的NESR。针对一种新型的级联积分球型大孔径NESR定标系统,开展了NESR定标不确定度的实验测试研究,评定了绝对光谱辐亮度的量值溯源、积分球输出的均匀性和稳定性等11种不确定性因素的影响。测试结果表明,在规定的303~308 K亮温范围内,主积分球光谱辐亮度的相对不确定度优于0.34%,6~15 μm波段的NESR定标不确定度优于0.1~0.0037 μW·cm?2·sr?1·μm?1,验证了新型定标系统应用于高性能红外遥感器NESR定标的可行性。     

宽动态范围红外积分球辐射源的优化设计与性能测试(特邀)

为满足红外遥感器高精度等效噪声光谱辐亮度的定标要求,在原有的设计基础上改进了红外积分球辐射源研制制造工艺,满足真空低温使用要求。该积分球辐射源采用8组碳纤维石英电热管作为红外辐射介质,实现工作波段覆盖3~15 μm,可调辐射动态范围提升1倍。设计了辐射定标与测量光路,通过比对测量标准腔式黑体辐射源,实现红外积分球辐射源真空低温条件下的辐射定标。定标结果表明:红外积分球辐射源出光口法线Ф200 mm范围内的面均匀性为99.75%,±10°范围内的角度均匀性为99.81%,非稳定性为0.05%。实现了红外积分球辐射源光谱辐亮度输出等色温近线性可调功能,5 μm和10 μm辐亮度可调范围分别达到12.8 μW/(cm2·sr·nm)和1.6 μW/(cm2·sr·nm)。     

双通道自校准辐射计与辐亮度标准探测器的比对实验研究

基于自发参量下转换的高精度自校准辐射基准源是目前卫星遥感定标的研究热点。本文介绍了双通道自校准辐射计的工作原理并搭建了实验装置,展开了与传统辐亮度标准探测器的比对实验验证。采用736.9nm激光导入积分球的单色均匀辐亮度光源,将双通道自校准辐射计和辐亮度标准探测器分别对积分球出口辐亮度进行探测,测得绝对辐亮度分别为4.69×10-9W/(sr?mm2)和5.19×10-9W/(sr?mm2),二者之间的相对偏差为9.63％,验证了研制的双通道自校准辐射计的原理可行性。     

一种空间相机辐射定标用大面积辐射光源的研制

针对目前空间光学遥感器向着大口径、高精度方向发展相应需要大出光面的积分球辐射光源,本文研制了一种大口径空间相机用积分球辐射定标光源,并使用自制的积分球辐射性能测试装置测试了大口径积分球光源的均匀性、余弦特性和稳定性。研制的积分球辐射定标光源内径为3000mm,出光面直径为1 000mm。测试结果表明,积分球的最大幅亮度为240.13 W·m-2·sr-1,辐亮度调节范围为371.5∶1,辐亮度不稳定性为0.04%/h,光源出口面非均匀性为1.7%,辐射定标光源的不确定度为5%。     

基于绝对辐亮度计定标的积分球紫外光谱辐射特性研究

针对积分球开口光谱辐射特性测量的复杂性及紫外波段标准光源不确定度大的缺点,构建了一种基于紫外标准探测器的高精度绝对辐亮度计。用所构建的绝对辐亮度计,以3个波长为例,标定积分球开口光谱辐亮度,修正了250~400 nm波段积分球开口光谱辐亮度曲线。同时,利用该绝对辐亮度计对积分球输出稳定性、积分球开口均匀性以及朗伯余弦特性进行了全面测试。积分球开口3个波长280,313和352 nm处光谱辐亮度定标合成标准不确定度分别为3.2%,3.0%和3.0%,积分球输出稳定性、开口均匀性以及朗伯余弦特性3个波长处合成标准不确定度分别为1.7%,1.6%和1.6%。不确定度分析表明用绝对辐亮度计研究积分球光谱辐射特性与传统的积分球光谱辐射特性研究相比方便可行且精度更高。     

超大口径均匀光源辐射性能设计与测试

目前光学遥感器向着大口径、宽视场的趋势发展,随着遥感器口径和视场的不断增大,需要与之对应的定标设备来满足其全口径全视场的定标要求。为此,研制了一套超大口径(3.2m)均匀光源系统。首先基于积分球理论和黑体普朗克理论设计出口光谱辐射亮度,并利用LightTools软件对出口均匀性和朗伯特性进行内置光源分布仿真设计。然后针对超大口径均匀光源辐射性能测试存在的问题,研制了一套基于阵列探测器的辐射性能测试装置,并应用校正算法进行一致性校正。最后利用新研制的设备对超大口径均匀光源进行测试实验,并对测试不确定度进行分析。结果显示:0.8m口径光源的光谱辐射亮度大于600 W·m~(-2)·sr~(-1),3.2m口径光源的均匀性优于98.362%,中心点±45°范围内朗伯特性优于98.810%,数据表明新研制的超大口径均匀光源满足设计要求。     

基于Dome C的SNPP和NOAA-20 VIIRS DNB在轨辐射定标精度及稳定性评估

基于夜间大气层顶反射率方向性分布特性,提出了一个基于精确模拟夜间辐射传输过程的低照度遥感载荷在轨辐射定标性能评估新方法。即以南极雪地Dome C为研究区,以MT2009（Miller-Turner 2009）大气层顶月球辐照度模型和大气层顶双向反射分布函数（Bidirectional Reflectance Distribution Function, BRDF）模型模拟的夜间星上辐亮度值为基准,分析相同几何条件下,可见光近红外成像辐射计夜间光波段（Visible Infrared Imaging Radiometer Suit Day/Night Band, VIIRS DNB）观测辐亮度与基准值之间的一致性,发现在2018-2020年两者差值保持在4.97×10^-10 W?cm^-2?sr^-1左右,比VIIRS DNB最小探测阈值3×10^-9 W?cm^-2?sr^-1约低一个数量级,故从可接受的仪器灵敏度误差范围内,可判定VIIRS DNB载荷在美国极轨合作卫星（Suomi National Polar-orbiting Partnership, SNPP）和美国国家海洋和大气管理局（NOAA-20）上在轨辐射定标性能均非常优良。另外,基于距离校正后的SNPP VIIRS DNB和NOAA-20 VIIRS DNB辐亮度开展了VIIRS DNB载荷在轨辐射定标稳定性分析,发现相同月相角下两载荷辐亮度一致性在6%以内。     

超连续谱激光-单色仪在偏振遥感器定标中的影响因素分析

偏振遥感器的相对光谱响应度和带内光谱响应非一致性是遥感器实验室定标的基本参数。文中利用新型的超连续谱激光作为单色仪的前置照明光源,搭建了一套基于超连续谱激光-单色仪的细分光谱扫描定标装置,可用于偏振遥感器的相对光谱响应度定标。实验中以490 、670、910 nm三个偏振通道作为例,分别在单色仪直接输出光和单色光导入积分球两种状态下,得到通道式偏振遥感器的相对光谱响应度结果,并对两种状态下定标光源的偏振特性进行了测量。实验结果表明,单色仪直接输出光模式下,光源存在明显的偏振度和偏振方位角变化,三个偏振通道的带内光谱响应非一致性分别为0.91%、4.25%和1.06%;而在单色光导入积分球后,光源的偏振度明显降低,此时带内光谱响应非一致性结果分别为0.15%、0.47%和0.57%,说明消偏后的光源能有效适用偏振遥感器的光谱响应度定标,基于超连续谱激光-单色仪的系统级定标装置在偏振遥感器的定标中具有广泛应用前景。     

高精度智能化可见/近红外积分球辐射定标装置

设计了由硅光电探测器作为反馈元件,采用DSP控制主光源开口处电动可调光阑大小,实现输出光谱辐亮度值连续可调的高精度程控化可见/近红外波段积分球辐射定标装置。经过理论设计和计算,在该装置内放置挡屏,保证了出射口处输出光谱辐亮度值的均匀性。使用PR-655高精度扫描式亮度计测量出该装置的最大输出光谱辐亮度值为23 061 cd/m2;在直径150 mm范围内的光谱辐亮度值的非均匀性为1.04%;输出光谱辐射亮度值的稳定性为0.8%。实验结果表明:该装置完全可以满足可见/近红外光学遥感仪器的地面辐射定标需要,并可实现智能程控化控制,提高了定标测试精度。     

星上定标积分球系统的设计

星上定标系统是有效监测遥感器辐射响应性能的重要技术构成,成像光谱仪技术的发展对星上定标系统提出了更高的要求,包括系统小型轻量化及稳定性等技术难题.提出一种较完整的技术方案,以内置卤钨灯为光源,用小型化的积分球为匀光体,采用色温校正技术调节其光谱输出,内置安装标准辐射计监视系统的稳定性.针对积分球系统定标用的光源--卤钨...     

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.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.