Author Affiliations
Abstract
College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China
In order to solve the problem of direction discrimination and low-speed measurement for a spatial filtering velocimeter, a method of frequency shifting is put forward. The filtering device is constructed by a CMOS linear image sensor that is employed both as a differential spatiotemporal filter and as a photodetector. Frequency shifting is realized by shifting the pixels of the image sensor, and the shifting is implemented digitally. The power spectrum of the output signal is obtained by fast Fourier transform (FFT). Given the limited resolution of FFT, a frequency spectrum correction algorithm, called energy centrobaric correction, is utilized to improve the frequency resolution. The built system is used to measure the transverse velocity of a simple pendulum. The results of theory analysis and experiments verify the feasibility of direction discrimination and low-speed measurement by the method of frequency shifting. Experimental results also show that the method of energy centrobaric correction can improve the velocity resolution by more than one order of magnitude.
Chinese Optics Letters
2015, 13(Suppl): S21204
国防科学技术大学光电科学与工程学院, 湖南 长沙 410073
随着激光技术的不断发展，高Q 值光学微腔受到广泛关注，其应用领域不仅局限于传统光学，在量子信息和集成量子芯片方面更是有广阔的应用前景。简要分析了两种不同类型光学微腔（回音壁模式光学微腔和光子晶体缺陷腔）的原理、发展历程以及相对于传统光学谐振腔的优势。同时数值模拟出了不同结构光学微腔的模式分布。基于其特殊优势，介绍回音壁模式光学微腔在激光技术、生物探测以及量子物理领域的重要应用，并且预测光子晶体微腔将在集成光学、微电子技术等领域具有巨大的发展前景。
集成光学 微腔 光子晶体 模式 激光与光电子学进展
2015, 52(4): 040002
国防科学技术大学光电科学与工程学院, 湖南 长沙 410073
初步研究了方形谐振腔环形激光器的背向散射耦合效应。用矢量法求解了方形谐振腔镜片位置变动对腔内稳态闭合光路的长度及形状变化的影响。根据背向散射矢量耦合理论，在对闭合光路变动进行分析的基础上建立了方形无源谐振腔背向散射耦合模型。此模型可以推广应用到任意形状环形腔的背向散射耦合效应的研究。理论上得到了背向散射耦合系数振幅与谐振腔腔长变化具有双波长周期关系。理论分析表明谐振腔体初始加工径向误差对于背向散射耦合效应有巨大影响。
激光技术 方形谐振腔 背向散射耦合效应 矢量法 环形激光器 光学学报
2011, 31(s1): s100522
