高次离轴凸非球面反射镜组合加工（特邀）

为提高离轴三反消像散（TMA）光学系统中次镜的制造效率和精度,开展了离轴凸非球面反射镜组合加工和零位检测的研究工作。首先,介绍了方形(298 mm×264 mm)高次离轴凸非球面反射镜的光学参数、技术指标和总体加工路线;其次,提出了铣磨加工工艺策略以及基于气囊和沥青的小磨头组合加工工艺;最后,阐述了光学零件抛光阶段采用的背部透射零位补偿检测法和Offner型零位补偿器,并采用光线追迹法对镜片的零位补偿检验面形畸变进行了矫正,最终面形RMS值为0.025λ （λ=632.8 nm）,满足技术指标要求。上述组合加工工艺和背部透射零位补偿检测方案可以显著提升高次离轴凸非球面反射镜的加工精度和效率。     

夏克哈特曼扫描拼接检测平面镜(特邀)

随着先进光学系统设计与制造的发展,大口径光学系统得到了广泛的应用。然而,大口径平面镜高精度面形的检测手段不足,限制了大口径平面镜的制造与应用。为实现大口径平面反射镜的高精度面形检测,提出一种夏克哈特曼扫描拼接检测平面镜面形的方法。对扫描拼接原理、波前重构算法进行了研究,建立了微透镜阵列成像的数学模型,验证了夏克哈特曼扫描拼接检测原理的可行性。针对一口径为150 mm的平面镜进行了扫描拼接检测实验,拼接得到的全口径面形为0.019λ RMS(λ=635 nm);与干涉检测结果对比,检测精度为0.008λ RMS,结果表明该方法能够实现大口径平面反射镜的高精度检测。     

红外天文光度计中反射式场光学系统的应用

本文论述了反射式场光学系统——凹面反射镜系统的结构和特点,以及它们应用于1～5.5μm红外波段时的优缺点。实验结果表明:凹面反射镜系统在上述红外波段可以得到满意的结果,缺点是它结构复杂,加工和调整相当困难。     

中小型圆形反射镜检测支撑优化

为了优化中小型圆形反射镜在加工、镀膜、装调等阶段的检测中所需的支撑结构,以V型块支撑工作原理设计了支撑位置及支撑点夹角均可调整的分体式支撑。利用有限元方法得到TMA系统中Φ136 mm非球面次镜面形随支撑点夹角的变化趋势,并根据趋势曲线,确定支撑点夹角为100°状态下,分体式支撑结构引起的镜面面形变化最小(RMS=0.57nm)。利用干涉仪结合补偿器的检测方式,对分体式支撑在不同的支撑点夹角下的镜面面形进行检测。所得结果与有限元方法得到的镜面面形随支撑点夹角变化趋势与试验结果相符,且在100°时分体式支撑引起的镜面面形变化(RMS=0.015 wave)明显优于其他角度。再以不同的镜坯材料及反射镜直径尺寸进行仿真对比,结果表明:镜面面形随支撑点夹角的变化趋势与反射镜材料和尺寸无关,趋势曲线幅值随材料弹性模量和反射镜直径改变而变化。优化得到的分体式支撑对于中小型圆反射镜具有广泛适用性。     

大口径SiC反射镜的焊接加工和测试

SiC是目前空间用大口径反射镜的首选材料,随着空间光学系统的发展,出现了1m以上空间用SiC反射镜的需求.对该反射镜采用焊接拼接然后再进行加工可以节约成本,降低风险.作为演示实验件,首先,对直径为600mm的焊接SiC反射镜进行了焊接拼接,粗磨成型、精细研磨和粗抛光.然后,采用CCOS技术对反射镜进行了精抛光,并分析了...     

大口径空间红外相机铍铝合金反射镜组件材料选择与设计

针对某空间摆扫相机系统，为了保证空间红外相机获得轻质、可靠的摆扫头部，且各反射镜均具有良好的面形精度及较高的一阶固有频率，对其摆扫部分的结构进行了针对性研究。选择了铍铝合金材料作为Φ750 mm口径主反射镜材料，以钛合金材料的柔性支撑结构支撑，安装在铍铝合金材料的主镜室内。包含次镜组件、次镜支撑和遮光筒，整个摆动部分总质量为17.5 kg。采用有限元方法对反射镜组件在力热耦合状态下进行了仿真分析，结果表明反射镜全口径最大面形误差RMS值为27.04 nm，满足全口径范围内面形误差不低于λ/20(λ=632.8 nm) 的要求。摆动部分一阶谐振频率为122 Hz，为控制系统预留了较大的带宽。实体模型的力学试验结果与有限元分析结果接近，表明满足总体对摆扫部分的设计要求。     

用于多光谱遥感器的离轴三反射镜光学系统的设计与检验

未来的航空侦察系统要求其光学系统在宽视场范围内具有高空间分辨率。该遥感器飞行高度为10km,在6°视场内需要分辨10cm的地面目标,光谱覆盖范围为0.4μm～10.0μm,包括可见光、近红外(NIR)、中红外(MWIR)和远红外(LWIR)。本文介绍了满足这些要求的离轴三反射镜光学系统的设计和相关的试验结果。三反射镜消像散系统包括两个非球面凹反射镜和一个球面凸反射镜,并实现了远心平像场设计。     

Φ450 mm口径空间天文相机轻量化碳化硅主反射镜组件设计

针对某空间天文相机对轻量化、光学效率、杂光抑制与探测能力的需求,设计Φ450 mm口径碳化硅主反射镜,镜体轻量化率超过70%;选取线膨胀系数匹配的殷钢材料,设计基于两脚架柔性结构的侧面支撑以消除装配应力和热应力,通过渗硅改性获取高反射率光学镜面。光学加工完成后反射镜质量7 kg,反射率优于98%。在严格的工艺条件控制下,对反射镜组件进行精密装配。光学检测结果表明,反射镜装配完成后面形误差优于0.02λ RMS,与分析结果吻合。证明了空间天文相机主反射镜组件结构设计方案与装调工艺的合理性,满足空间天文相机光学设计要求。     

应用于红外光学系统的铝合金反射镜面型变形研究

铝合金反射镜应用于红外光学系统中,其表面变形会对光学系统成像质量造成较大影响。通过光学系统传递函数测试仪器进行大量的实际传递函数测试可以得出变形铝合金反射镜对整机传递函数主要的影响情况。通过分析影响,并在光学系统设计软件中进行仿真,得出铝合金反射镜的主要变形特点,即铝合金反射镜整体和局部的曲率误差。建立了整体和局部曲率误差的表面面型模型,定量化分析了变形对成像质量的影响。针对典型的变形特点,改进了安装方式,使反射镜受力均匀,其变形情况得到缓解,从而保证光学系统的成像质量达到要求。     

深低温SiC空间反射镜背部与侧面支撑结构对比

在深低温下的反射镜及其支撑结构设计中,温度变化作用下的面形精度是空间反射镜性能的重要影响因素。以温度变化作用下的面形RMS为性能指标,基于碳化硅反射镜不同支撑结构和不同材料搭配形式下对空间反射镜的面形变化进行对比研究。首先,在深低温下对背部支撑和侧面支撑的以下两种情况进行仿真分析:(a)反射镜和支撑结构都用碳化硅制造;(b)反射镜用碳化硅制造,支撑结构用其他材料制造。仿真分析得到在(a)条件下背部支撑结构能获得更好的面形,在(b)条件下,侧面支撑结构能获得更好的面形;然后对侧面支撑结构中不同材料搭配情况下对面形精度的影响进行研究,对面形RMS与反射镜材料的线膨胀系数,支撑结构材料的线膨胀系数和反射镜材料与支撑结构材料的线膨胀系数之差的绝对值之间的关系用多元线性回归方法进行统计分析,研究其影响程度,分析得到线膨胀系数之差的绝对值对面形精度RMS的影响更大。研究取得的成果和研究思路对今后的深低温光学反射镜及其支撑结构设计提供参考。     

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.     

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.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.