Author Affiliations
Abstract
1 Institute of Optoelectronics Technology, China Jiliang University, Hangzhou 310018, China
2 School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Using the first-principles method based on the density functional theory (DFT), the work function of seven different GaN (0001) (1×1) surface models is calculated. The calculation results show that the optimal ratio of Cs to O for activation is between 3∶1 and 4∶1. Then, Cs/O activation and stability testing experiments on reflection-mode negative electron affinity GaN photocathodes are performed. The surface model [GaN (Mg): Cs] Cs-O after being activated with cesium and oxygen is used. The experiment results illustrate that the adsorption of O contained in the residual gas increases the surface potential barrier and the reduction of the effective dipole quantity is the basic cause of the quantum efficiency decay.
040.7190 Ultraviolet 160.1890 Detector materials 230.0040 Detectors 260.7210 Ultraviolet, vacuum Chinese Optics Letters
2015, 13(10): 100401
中国计量学院现代计量测试技术及仪器浙江省重点实验室, 浙江 杭州 310018
采用紫外(UV)辐射固化荧光粉胶层。研究UV胶中各个成分对固化膜透射率的影响，找出透射率最高的匹配比例。用最佳比例的UV胶和荧光粉混合，与传统荧光胶对比，观察荧光粉沉降现象。分别用UV胶和AB胶封装LED，测量LED的光学性能，通过对比研究紫外固化对LED光学性能的影响。研究发现荧光粉在UV胶中沉降现象比AB胶中不明显；与AB胶封装的LED对比，UV荧光粉胶对LED的光谱分布、显色指数、相对色温和光通量等光学性能没有明显的影响和改变。
光学器件 紫外固化 封装 荧光粉 透射率 显色指数 激光与光电子学进展
2013, 50(2): 022301
Author Affiliations
Abstract
Surface photovoltage spectroscopy equations for cathode materials with an AlxGa1 xAs buffer layer are determined in order to effectively measure the body parameters for transmission-mode (t-mode) photocathode materials before Cs-O activation. Body parameters of cathode materials are well fitted through experiments and fitting calculations for the designed AlxGa1 xAs/GaAs structure material. This investigation examines photo-excited performance and measurements of body parameters for t-mode cathode materials of different doping structures. It also helps study various doping structures and optimize structure designs in the future.
040.7190 Ultraviolet 160.1890 Detector materials 230.0040 Detectors 260.7210 Ultraviolet, vacuum Chinese Optics Letters
2012, 10(11): 110401
1 中国计量学院 光学与电子科技学院,杭州 310018
2 杭州电子科技大学 电子信息分院,杭州 310018
用基于德拜近似条件的矢量衍射理论研究了带有相位拓朴数的环形相位板调控高斯光束的光梯度力分布,改变相位板环形区的相对半径或当相位板的相位以一定拓扑数呈现拓扑变化时,可以调节光学系统焦点区域的光梯度力分布,形成各种非常有规则的几何形状的光陷阱,如当拓朴数分别取3,4,5,6时,可形成三角形、四边形、五边形和六边形光陷阱。此种相位板可用来构建可调的光镊系统,且通过调节相位板的各区域半径和拓扑数可以得到所希望的光陷阱。
梯度力 相位板 高斯光束 光陷阱 矢量衍射理论 拓朴 Gradient force Phase plate Gaussian beam Optical trap Vector diffraction theory Topology
