First-principles calculations of electronic structures and absorption spectra of YAlO3 crystals with F center

National Nature Science Foundation of China (Grant No. 60607015)

光学薄膜膜厚自动控制系统的研究

介绍了一种利用光电极值法同时控制规整膜系和非规整膜系的方法,利用VC＋＋编写程序实现对光学监控信号的采集、处理及停镀点的自动判断,实现了规整膜系和非规整膜系膜层厚度的自动控制.并利用该膜厚自动控制系统实验制备了规整膜系和非规整膜系多层膜,实验结果表明：利用该系统镀制的薄膜重复性良好,且光谱曲线和理论光谱曲线吻合较好.该系统解决了非规整膜系的监控问题,由计算机控制膜层的停镀点,排除了人的主观因素对薄膜的性能及其制备的重复性产生的影响,提高了薄膜镀制的重复性和成品率.

Design of high-efficiency diffraction gratings based on rigorous coupled-wave analysis for 800nm wavelength

We report on the design of a high diffraction efficiency multi-layer dielectric grating with wide incident angle and broad bandwidth for 800 nm. The optimized grating can achieve > 95% diffraction efficiency in the first order at an incident angle of 5 degrees from Littrow and a wavelength from 770nm to 830 nm, with peak diffraction efficiency of > 99.5% at 800 nm. The electric field distribution of the optimized multi-layer dielectric grating within the gratings ridge is 1.3 times enhancement of the incidence light, which presents potential high laser resistance ability. Because of its high-efficiency, wide incident, broad bandwidth and potential high resistance ability, the multi-layer dielectric grating should have practical application in Ti:sapphire laser systems.