基于分光光度法的差分信号精确测量高反镜反射率  

Accurate Measurement of Reflectivity of High Reflectivity Mirror by Differential Signal Based on Spectrophotometry

作　　者：胡晨璐 李大伟[1,3] 刘晓凤[1,3] 李笑玲 赵元安[1,2,3] 邵建达 王琨[1,5] 龚赫 陶春先 Hu Chenlu;Li Dawei;Liu Xiaofeng;Li Xiaoling;Zhao Yuanan;Shao Jianda;Wang Kun;Gong He;Tao Chunxian(Laboratory of Thin Film Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Materials for High Power Laser,Chinese Academy of Sciences,Shanghai 201800,China;Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024,Zhejiang,China;School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]中国科学院上海光学精密机械研究所薄膜光学实验室,上海201800 [2]中国科学院大学材料与光电研究中心,北京100049 [3]中国科学院强激光材料重点实验室,上海201800 [4]中国科学院大学杭州高等研究院,浙江杭州310024 [5]上海理工大学光电信息与计算机工程学院,上海200093

出　　处：《中国激光》2023年第10期87-92,共6页Chinese Journal of Lasers

基　　金：国家重点研发计划(2018YFE0115900);国家自然科学基金(11874369,52002271);中国科学院国际合作局对外合作重点项目(181231KYSB20210001)。

摘　　要：目前,高反射率反射镜在激光陀螺和引力波探测等领域中有着广泛的应用。但对于反射率为99.9%~99.99%的样品,现有测试手段存在一定局限性。搭建了基于分光光度法的反射率测量装置,采用双光路测量方法,通过测量参考信号和基准信号、参考信号和测试信号的差分信号来计算反射率。与绝对值较大的参考信号、基准信号和测试信号等相比,信号差值本身相对较小,因此可以充分利用锁相放大器的灵敏度来提高反射率的测量精确度。所介绍的测量方法的精确度可达10-5,与光腔衰荡法进行对比,测量误差在0.009%以下。所提方法用简单的装置就能达到较高的精确度,满足99.9%~99.99%反射率的精确测量需求。Objective Currently,high-reflectivity optical elements are widely used in optical fields,such as ring laser gyroscopes,inertial confinement fusion systems,and gravitational wave detection.Their reflectivity values have a decisive influence on the performance improvement of these systems;therefore,accurate measurement of their reflectivity values is necessary to optimize the system performance.At present,there are many measurement methods,among which spectrophotometry and cavity ring-down(CRD)technology are the most widely used.However,these two methods have certain shortcomings.Spectrophotometry is associated with low accuracy,and its measurement limit is usually lower than 99.9%;especially when measuring high reflectivity(>99%),its accuracy is reduced.Devices using CRD technology for high reflectivity measurement are relatively complex and expensive,and the measurement conditions,such as adjusting the incident angle and polarization state,are inflexible.Moreover,according to the measurement principle,the lower the reflectivity of the sample to be measured,the lower is the measurement accuracy.Therefore,for samples with the reflectivity of 99.9%‒99.99%,existing testing methods have some limitations.Based on the described situation,it is necessary to study a high-precision reflectivity measuring device that can measure the reflectivity of 99.9%‒99.99%accurately.It is necessary to develop a reflectivity measuring device which has the advantages of simple device,convenient adjustment and good measurement stability.Methods Based on traditional spectrophotometry,we study a more accurate reflectivity measurement method.The main improvement in this method is measuring the difference signal instead of the reflected light and incident light signal.In this study,a reflectance measuring device based on spectrophotometry is developed,which adopts a double-path measurement.First,we measure the signal difference between the reference optical path and the initial optical path without samples,and the reference optical path s

关 键 词：测量 激光光学 高反射率 分光光度法 光学薄膜 锁相放大器 

分 类 号：O435[机械工程—光学工程]