基于光纤激光频率分裂效应的折射率/厚度双参量测量研究  

Measurement of refractive index and thickness based on the fiber laser frequency splitting effect

作　　者：陈恺 祝连庆[1,2] 刘昭君[2] 鹿利单 庄炜 Chen Kai;Zhu Lianqing;Liu Zhaojun;Lu Lidan;Zhuang Wei(School of Instrument Science and Opto-electronics Engineering,Hefei University of Technology,Hefei 230009,China;Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument,Beijing Information Science&Technology University,Beijing 100192,China)

机构地区：[1]合肥工业大学仪器科学与光电工程学院,合肥230009 [2]北京信息科技大学光电测试技术及仪器实验室,北京100192

出　　处：《仪器仪表学报》2021年第11期27-34,共8页Chinese Journal of Scientific Instrument

基　　金：高等学校学科创新引智计划(D17021);国家自然科学基金(61903042)项目资助。

摘　　要：折射率作为光学系统中应用最广泛的光学参数之一,对系统的光学性能具有极其重要的影响。厚度与折射率所组成的光学长度直接影响双折射器件在光学系统中的时延特性。本文提出一种基于光纤激光频率分裂效应的折射率/厚度双参量测量方法。该系统通过对插入激光腔内的双折射器件进行旋转,利用频率分裂效应对不同角度的器件的双折射参数进行测量。基于双折射器件中的折射率椭球,建立相位延迟、折射率、厚度和旋转角度之间的关系,通过拟合计算得到器件的折射率/厚度参数。实验结果表明,通过该系统对双折射元件的厚度测量误差为210 nm,本征折射率进行测量误差为10^(-5),可广泛应用于红外波段的双折射器件的本征折射率/厚度双参量测量。Refractive index is the most widely used optical parameter in the optical system,which has an extremely important influence on the optical performance.The optical length consists of refractive index and thickness,which directly affects the time delay characteristics of birefringent devices in the optical system.In this article,a measurement method of refractive index and thickness based on the fiber laser frequency splitting effect is proposed.By rotating the birefringent device inserted into the laser cavity,the birefringent parameters of the device at different angles are measured by using the frequency splitting effect.Based on the refractive index ellipsoid of birefringent device,the relationship among phase delay,refractive index,thickness and rotation angle is established.The refractive index and thickness parameters of the device are achieved by fitting calculation.Experimental results show that the thickness measurement error of birefringent elements is 210 nm,and the intrinsic refractive index measurement error is 10^(-5).It could be widely used in the measurement of intrinsic refractive index and thickness of birefringent elements in the infrared band.

关 键 词：光纤激光 频率分裂 折射率 厚度 双参数测量 

分 类 号：TH744[机械工程—光学工程] O439[机械工程—仪器科学与技术]