Extremely wide band Rayleigh resonant reflector with sharp angular spectra in near infrared wavelength band

In this paper, we propose an extremely broadband Rayleigh resonant reflector with sharp angular spectra operating in near infrared wavelength band, this device consisting of a single germanium resonant grating layer is designed and analyzed by using with the rigorous vector diffraction theory. At the Rayleigh angle, the first diffracted order can be appear from evanescent to a propagating one, thus, a very sharp angular spectrum characteristics can be presented in the device. Based on the guided mode resonant effect, high index material such as silicon and germanium can be designed as wide band reflector, beam splitter and polarizer in near infrared wavelength region. Through connecting Rayleigh phenomena and guided mode resonant effect, we can design a new kind of optical devices with versatile characteristics such as sharp angular spectra and extremely wide reflection band. In this paper, we present a Rayleigh resonant reflector with extremely high reflection (R > 99.5%) for TE polarization light over ∼600 nm wavelength range and sharp angular spectral distribution. In addition, it is shown from our calculations that the high-index nano-layer located adjacent to the substrate is seen to critically affect the resulting spectra of Rayleigh resonant reflector.     

反射面形状对光纤位移传感器光强调制特性的影响

为了分析反射面形状对单模光纤照射的光纤位移传感器光强调制特性的影响,建立了反射面不为平面时的光强调制特性函数模型.该模型基于单模光纤出射光场为修正近似高斯分布假设,通过引入反射面形状因子,分析了反射面形状因子对光强调制特性的影响规律.仿真结果表明,随着凹形反射面曲率半径值的增大,传感器特性曲线的前坡无显著变化,而后坡灵敏度增大,线性范围减小|随着凸形反射面曲率半径值的增大,传感器特性曲线的前坡仍无显著变化,而后坡灵敏度减小,线性范围增大|当曲率半径增大的一定值时,反射面的非平面性影响较小,其作用趋近于平面.     

反射镜浮动支撑的应力与变形分析及支撑参数的优化

本文利用有限元分析对均匀压力浮动支撑的反射进行了应力、变形分析,利用优化方法计算了反射镜面变形的RMS值,并给出了均匀压力浮动支撑的最佳接触角。     

光纤F-P腔反射面的形变与传感应用研究

建立了反射端面为弧形形变的光纤F P传感腔数学模型.将弧形形变的F P腔等效为阶梯分布的、环状、平行端面F P腔体的组合,结合多光束干涉理论,利用光强叠加处理方法对弧形腔输出光强进行数学建模.依所建模型仿真,提出弧形端面曲率大于300 μm时,利用弧形形变特性进行传感测量的可行性.选取腔长变动大、形变弧度小,平衡状态稳定性高的形变端面保证传感腔的高灵敏度和稳定的工作点.     

基于分布式布拉格反射镜微腔的红绿蓝聚合物发光电化学池高色纯度光源

基于高色纯度的光源的显示技术具备宽色域、高色彩饱和度和高对比度的特点,能够给人们带来更好的视觉体验。近年来窄带宽光源的研制受到越来越多学者的关注。本文选择了三种典型的发光聚合物构筑聚合物发光电化学池(PLEC),利用分布式布拉格反射镜(DBR)和铝薄膜为腔对出射光谱进行窄化。结果表明,红绿蓝三色聚合物发光电化学池出射光的带宽可缩短至10、11和8 nm,色纯度得到了极大的提升。这种高色纯度光源的获得有望显著推动下一代显示技术的发展。     

月基极紫外相机反射镜组件的设计

为了使月基极紫外相机反射镜组件在月球环境下具有良好的力学和热学稳定性,从而保证相机的成像质量,本文针对月基极紫外相机所处的严酷的力学和温度条件,设计了一种满足月球环境的反射镜组件结构.通过对反射镜组件有限元模型的重力分析、热载荷分析、动态刚度分析以及结构强度分析,结果表明反射镜组件的一阶谐振频率达到354 Hz,在1 g重力作用和△T=50℃均匀温变作用下镜面综合面形误差RMS值分别达到3.62 nm和2.46 nm,满足反射镜面形要求.最后,通过静力学面形检测、力学试验、温度适应性试验及成像分辨率测试,结果显示反射镜镜面面形精度RMS值优于14 nm,反射镜组件的设计满足总体指标,验证了该方案的合理性.     

垂直腔面发射激光器的结构生长及特性研究

在偏〈111〉A 2°的GaAs (100) 衬底上生长了Al0.9Ga0.1As /Al0.2Ga0.8As周期结构的垂直腔面发射激光器（VCSEL）外延片P 型DBR的周期数为24.5对,N型DBR的周期数为34.5对.用光荧光 (PL) 谱、扫描电子显微镜 (SEM)和X射线双晶衍射 (XRD) 方法对VCSEL的光学特性和结构特性进行了分析室温量子阱材料的PL谱峰值波长为837.0 nm,半高宽达到28.9 nm在X射线双晶衍射回摆曲线中,除了“0”级衍射峰外,还观察到一级和二级卫星峰.“0”级双晶衍射峰的半高宽为12.56弧秒(″),衬底GaAs的衍射峰半高宽为11.79″.“0”级衍射峰半高宽与衬底GaAs的衍射峰半高宽比较接近,表明晶格具有很高的完整性.实验结果表明腔模波长为837.2 nm,腔模波长与PL谱峰值波长相匹配.     

Bragg Reflectors and Resonators in Microstrip Technology Based on Electromagnetic Crystal Structures

Recently, new promising two-dimensional (2-D) Photonic Bandgap Structures (PBG), or more properly Electromagnetic Crystal Structures, for microstrip lines have been proposed. In this paper, we analyze these structures in a manner like a Bragg reflector in optical wavelengths. Joining two of such Bragg like reflectors by means of a conventional microstrip transmission line allows one to design Bragg Resonators. The 2-D periodic pattern of the electromagnetic crystal structure is implemented with circles etched in the ground plane of the microstrip line by means of a numerical milling machine. Simulations have been performed by using HP ^TM Momentum and MDS software, and in accordance with the measurements give, for the Electromagnetic Crystal Structures, new promising potential applications both in microwave and millimeter wave integrated circuits, and also in the experimentation of expensive short wavelength (including photonic) devices by using simpler and cheaper microwave down scaling.     

基于光子晶体异质结的高效太阳能电池反射器研究

设计了一种可用于太阳能电池反射器的二维三角晶格光子晶体异质结结构.采用传输矩阵法对该结构在可见至近红外波长范围入射电磁波的反射率进行了模拟计算,并比较了不同入射方向下反射率的变化.结果表明,光线垂直入射时,该结构光子晶体对近红外波段入射光可实现完全反射|随着偏转角度的增大,在整个可见-近红外波段均显示出极高的反射特性.该结构有望用于制作覆盖整个可见光-近红外波段的高效全方位反射器.