LED扩展光源等光强的光学设计方法

LED是一种新型的光源,具有传统光源无法比拟的优点。目前,LED应用于路灯、汽车灯等许多地方,但是这些设计主要是针对照度分布的光学研究,对光强的设计涉及得较少,尤其是大功率LED扩展光源。文章提出了一种对于LED扩展光源等光强的自由曲面设计方法。首先根据二维光学扩展量守恒,计算出出射宽度L,然后根据光强与照度关系推导出三维补偿系数,弥补了二维设计下的用旋转轴对称的所产生的误差。用Matlab软件逐步计算设计,把生成点导入建模软件中得出实际模型,经光学软件经仿真后,观察目标面的结果,发现光强均匀性达到82%,效率也超过95%。     

基于经纬划分和切面迭代的自由曲面LED透镜设计

根据非成像光学原理,提出了基于经纬划分和切面迭代的自由曲面求解方法。先在三维坐标系中建立自由曲面与目标面的相对位置模型,并对自由曲面沿经纬方向角度均分;再根据自由曲面各经纬带上能量与目标面各微带上能量对应相等,实现目标面网格划分并求得与自由曲面各网格对应的目标节点坐标;选取自由曲面初始网格节点,利用Snell方程和切面迭代法,沿经纬方向分别求解,得自由曲面各节点坐标,即可拟合成所求自由曲面。对用该方法设计的LED透镜进行模拟,结果表明对于目标面为轴对称区域的均匀照明,该方法可快速精确地获得对应的光学系统,使得LED光源能够广泛应用于道路照明系统中。     

基于LED光源的新型准直透镜的设计

利用复合抛物面与自由曲面相结合的方法,设计出一款体积小、能效高的LED光源准直配光透镜。将LED光源发出的光线分两部分分别进行配光设计。光源发出的一部分发散角为0o~20o的光线经过球冠折射收缩发散角后再利用自由曲面准直;光源发出的另一部分发散角为20o~80o的光线经过复合抛物面折射收缩发散角后再经自由曲面准直。结果显示,LED光线经此复合型准直透镜后光束发散角小于4o,光能利用率达90%,可满足目前对光源远距离准直需求。     

用于LED光源准直的紧凑型光学系统设计

设计了一种光学系统,用于发光二极管(LED)光源准直,并通过TracePro软件仿真进行了验证。该系统采取了折射和反射式自由曲面的组合,使LED光源的发散角从70°减少到约4°,效率在约85%,系统的高度为7.65mm,口径为8.73mm。分析了折射和反射的最佳分界角区域是41°～45°,最佳分角比例因子是0.4～0.5。     

基于非成像光学的LED路灯透镜设计方法

LED作为新型的绿色光源,在道路照明领域迅速发展.道路照明要求LED路灯在路面形成均匀性良好的矩形光斑,这就需要设计自由曲面透镜来达到配光要求.简要介绍了目前常见的自由曲面透镜设计方法,并就偏微分方程法和网格法进行了详细介绍与比较,认为网格法更具有良好的研究前景.     

自由曲面透镜白光LED光束整形技术

为了获得高均匀性、对称性及一些特殊形状强度分布的白光发光二极管(LED)光束以满足某些特定的需求, 基于白光LED光源为朗伯光源的特性, 运用自由曲面透镜的方法对LED光束进行了光束整形, 分别采用单一自由曲面透镜以及全内反射(TIR)透镜与微透镜阵列组合两种不同的整形结构, 进行了加工工艺和原理理论分析, 并通过了实验验证。结果表明, 实验得到的圆形均匀光斑, 其总光线利用率高达96%, 有效面积光线利用率为88.4%;得到的矩形均匀光斑, 总光线利用率为91%, 有效面积光线利用率为78.7%, 光束均匀度均在60%以上; 通过自由曲面透镜方法进行白光LED光束整形效果极佳。该整形方法为白光LED光源的进一步广泛应用提供了重要的指导。     

基于照度分割反馈法的扩展光源背光源设计

以LED为扩展光源,提出一种基于照度分布分割与反馈的方法为LED设计非常紧凑的光学自由曲面透镜,进而设计实现了大距高比(DHR)的直下式背光源.与子光学面联接构成光学面的过程相对应,总照度分布被分割为子照度分布.通过修正子光学面来调整子照度分布,使得总照度分布足够接近于目标照度分布,所需光学面就被构建出来了.该设计过程不依赖于仿真,简便易行,适用广泛.作为实例,一个非常紧凑(透镜的中心高度与LED尺寸相等)的自由曲面透镜被设计出来,作为直下式背光源的配光透镜.仿真结果表明,背光源照度分布的均匀度达到了0.91,相对标准差(RSD)低至0.020 2,总的光能利用率达到了85.5％.     

激光光源汽车前照灯自由曲面反射器设计EI北大核心CSCD

文中针对激光前照灯的光学结构设计困难和能量利用率低的问题,以球面最优传输理论为基础,提出了一种新的自由曲面反射器设计方法。该方法基于支撑曲面的结构,针对扩展光源进行了优化,有效抑制了目标照明区外的照度,实现了清晰的明暗截止线。文中根据GB 25991—2010标准,设计了适用于激光前照灯(含近光灯和远光灯)的自由曲面反射器,并使用扩展朗伯光源进行模拟仿真。仿真结果表明,配光屏幕上各测试点和测试区域的照度均符合法规要求,反射面连续光滑,能量利用率分别为96.96%和97.80%。通过实现高能量利用率的结构,减少了汽车前照灯的功耗,利于汽车前照灯的散热设计,延长了激光光源使用寿命,并为设备的生产加工带来便利。     

实现大范围均匀照明的LED透镜二次光学设计

提出了一种新的、利于实施计算的实现大范围均匀照明的LED灯具透镜设计方法。基于能量守恒定理和光线折射Snell定理,通过Matlab编程计算出自由曲面透镜坐标点。借助CAD软件和光学模拟软件Tracepro,模拟了自由曲面透镜的具体应用,在光源高为3m,接收面直径为10m的圆形照明区域,得到了均匀度达80%以上的照度分布,该设计可以应用在商场、工厂等室内照明灯具上。     

LED自由曲面准直透镜的优化设计方法

提出了一种自由曲面准直透镜的优化设计方法。通过对二次B样条理论、Scheme语言和优化引擎的结合使用,实现了准直透镜的优化设计。采用1 mm×1 mm朗伯体发光的LED作为光源,透镜材料为聚甲基丙烯酸甲酯(PMMA),通过对两款不同结构准直透镜的优化设计,可以实现发散角为±5°的准直照明,能量利用率均可达90%以上。与现有的优化方法相比较,此方法具有对初始模型依赖较低、设计方法简单和普适性高等特点。     

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.