基于等效元件和相位补偿法的双倍分辨率波片测量  

Double⁃Resolution Wave Plate Measurement Based on EquivalentComponents and Phase Compensation

作　　者：陈强华 邵多 刘福铭 关裕 吕洪波 司丽娜 阎红娟 豆照良 Chen Qianghua;Shao Duo;Liu Fuming;Guan Yu;LüHongbo;Si Lina;Yan Hongjuan;Dou Zhaoliang(School of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学机械与材料工程学院,北京100144

出　　处：《中国激光》2024年第8期94-99,共6页Chinese Journal of Lasers

基　　金：国家自然科学基金(52075004,50475177,51575004);北京市教育委员会科学研究计划项目(KM202110009010);北京市自然科学基金(3212003)。

摘　　要：提出了一种基于等效元件和相位补偿法的高精度任意波片相位延迟量和方位角同时测量的方法。在测量光路中的待测波片之前插入一个可旋转半波片,利用反射镜使测量光两次过该半波片和待测波片,相当于测量一个相位延迟量为待测波片两倍的等效波片,可以实现双倍分辨率检测。采用双频激光源和相位检测方式,旋转半波片补偿测量光相位,将测量光相对参考光的相位差变化先后调整为最大值和最小值,由二者之差即可得到任意待测波片的相位延迟量,同时根据最大值或最小值对应的半波片方位角即可确定待测波片的方位角。本方法所测量的波片相位延迟量从原理上避免了一般光强法所受到的光强波动的影响,以及许多方法所受到的双折射器件方位角定位精度的影响。系统采用双频外差干涉光路,具有共光路性质,稳定性高。测量系统结构简单、元件少,测量快捷。此外,由于测量光束两次通过待测波片的同一位置,因此所提方法还可以用于测量楔形结构的双折射器件。现有条件下的误差分析表明,相位延迟量的测量不确定度约为3.3',快轴方位角的测量不确定度优于5.4''。实验对比结果表明所提方法与其他方法测量结果的一致性很好。Objective Wave plates are a key component of optical polarization systems.The study of methods to measure wave plates precisely is becoming increasingly important with continuous improvements in the performance of polarization systems.Currently,most techniques are based on detecting the intensity of light passing through a wave plate.These methods are generally susceptible to fluctuations in the intensity of the light.In contrast,other methods that measure the phase of the light instead typically exhibit greater accuracy and stability.However,relatively few such methods have been described in the relevant literatures for phase measurement.In this study,a high-precision method based on equivalent components and phase compensation is proposed to simultaneously measure the phase retardation and azimuth of arbitrary wave plates.Methods We insert a rotatable half wave plate in front of a measured wave plate and use a reflector to allow the measurement light to pass through both twice.This effect is equivalent to measuring an equivalent wave plate with a phase retardation twice that of the measured wave plate,and double-resolution detection is thus obtained.The proposed system includes a dual-frequency laser source and a phase detector.Simultaneously,the fast-axis azimuth is also determined according to the azimuth of the half wave plate when the maximum or minimum phase difference occurs.Results and Discussions An analysis of error values under the experimental conditions indicated that the measurement uncertainty of the phase retardation was about 3.3',and that of the fast-axis azimuth was better than 5.4''.The results of an experimental comparison show good agreement with the measurement results obtained using other methods.The proposed approach theoretically avoids the influence of fluctuations in the intensity of measurement light that affect conventional methods as well as the typical issue of the influence of the positioning accuracy of birefringent devices azimuth.The proposed optical system adopts a dualfreque

关 键 词：测量 波片测量 相位延迟量 等效元件 相位补偿 双倍分辨率 外差干涉 

分 类 号：O436.3[机械工程—光学工程]