基于双弹光级联差频调制的应力双折射二维分布测量  

Measurement of two-dimensional distribution of stress birefringence based on dual photoelastic modulators cascade difference frequency modulation

作　　者：李克武 邱元芳[2] 崔志英 毛磊 王志斌 匡翠方[1,2] LI Kewu;QIU Yuanfang;CUI Zhiying;MAO Lei;WANG Zhibin;KUANG Cuifang(College of Optical Science and Engineering,Zhejiang University,Hangzhou 310014,China;Ningbo Yongxin Optics Co.,Ltd,Ningbo 315040,China;Engineering and Technology Research Center of Shanxi Province for Opto-electric Information and Instrument,North University of China,Taiyuan 030051,China)

机构地区：[1]浙江大学光电科学与工程学院,浙江杭州310014 [2]宁波永新光学股份有限公司,浙江宁波315040 [3]中北大学山西省光电信息与仪器工程技术研究中心,山西太原030051

出　　处：《光学精密工程》2023年第18期2647-2655,共9页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.62205309,No.62205310,No.62125504)。

摘　　要：为了实现对光学材料、光学元件的快速、高精度应力双折射测试评估分析,本文提出了一种基于双弹光级联差频调制的应力双折射二维分布测量方案。将两个工作在不同频率的弹光调制器级联,构成偏振测量装置。光学材料和元件的应力双折射延迟量和快轴方位角参数,被加载到偏振测量装置的调制信号中;采用数字锁相技术,提取调制信号的基频项和差频项,然后完成应力双折射延迟量和快轴方位角两个参数求解;按照原理分析,研制了测试系统,并完成了系统初始偏移值定标;采用波片进行了测量精度和重复性测试,并完成了BK7玻璃样品的应力双折射分布测量实验。实验结果表明,该系统的快轴测量重复性为0.01°,双折射延迟量测量重复性为0.02 nm,单数据点测量时间小于200 ms。本文方案实现了高速、高精度和高重复度的应力双折射测量,同时具备应力双折射二维分布测量能力,可为波片、玻璃或晶体等光学材料双折射测量分析和评估提供有效手段。In order to achieve fast and high-precision measurement and analysis of stress birefringence in optical materials and optical components,this paper proposes a method for the two-dimensional distribu⁃tion measurement of stress birefringence based on based on dual photoelastic modulators cascade difference frequency modulation.Two photoelastic modulators operating at different frequencies are cascaded to form a novel polarimetry.The retardance and fast axis azimuth of the stress birefringence are loaded into the modulation signals.Employing digital phase-locked technology,the fundamental and differential fre⁃quency harmonic terms are extracted,and then the two parameters of stress birefringence are solved out.According to the principle analysis,the system is developed,and the initial offset value of the system are calibrated.A wave plate is used to measure accuracy and repeatability,and the stress birefringence distri⁃bution measurement experiment is completed with a BK7 glass sample.The experimental results show that the repeatability of fast axis azimuth and retardance is 0.01°and 0.02 nm,respectively,and the mea⁃surement time of a single point data is less than 200 ms.The scheme realizes high-speed,high-precision and high-repeatability stress birefringence measurement.The method demonstrate the ability to measure the two-dimensional distribution of stress birefringence.This provides an effective means for the analysis and evaluation of birefringence measurement of optical materials such as wave plates,glass or crystals.

关 键 词：弹光调制 差频调制 应力双折射 延迟量 快轴方位角 

分 类 号：O436.3[机械工程—光学工程] TH744[理学—光学]