基于偏振光栅的同步移相剪切干涉测量方法  

Synchronous Phase-Shifting Shearing Interferometry Based on Polarization Grating

作　　者：蒋金威 郭仁慧[1] 钱宇 刘杨 薛亮 李建欣[1] Jiang Jinwei;Guo Renhui;Qian Yu;Liu Yang;Xue Liang;Li Jianxin(School of Electronic and Optical Engineering,Nanjing University of Science&Technology,Nanjing 210094,Jiangsu,China)

机构地区：[1]南京理工大学电子工程与光电技术学院,江苏南京210094

出　　处：《光学学报》2024年第3期103-114,共12页Acta Optica Sinica

基　　金：国家自然科学基金(62171225,U2031131,61975079)。

摘　　要：针对在波前测试时,参考镜面自身面形误差、光能利用率不足、环境振动和空气扰动等对干涉测量结果的影响,提出一种基于偏振光栅(PG)分光的同步移相剪切干涉测量方法,通过将横向剪切干涉与同步相移技术相结合实现待测波面的准共光路相移测量。该方法采用1/4波片、PG和平面反射镜的组合作为横向剪切结构,可获得两束剪切的正交线偏振光,线偏振光经二维相位光栅、透镜、小孔光阑和相位延迟阵列构成的同步移相结构后,在CCD上可同时采集到4幅移相剪切干涉图。对x和y方向的剪切干涉图采用基于相位相关的图像配准算法、四步移相算法以及基于离散余弦变换法(DCT)的相位解包裹算法进行处理,得到差分相位分布,再用基于差分Zernike多项式的最小二乘波前重构算法对其进行重构,得到待测波面。通过搭建实验装置对一块透镜和凹面反射镜进行测量,结果表明,该方法的测量结果具有准确性和稳定性,该方法能够很好地应用于波前动态测量,对透射波前和光学元件的面形检测具有重要意义。Objective In the precision polishing stage of optical element processing,optical interference detection methods are often employed to detect the surface shape and transmitted wavefront.Among them,the shearing interference method is a measurement technology that adopts its light wave and copied light wave,and there is a dislocation between the light wave and copied light wave in space,which makes it unnecessary to introduce the reference light wave.At present,the synchronous phase-shifting technology is the interference measurement method with the best anti-vibration effect.It can obtain multiple phase-shifting interferograms spontaneously,and then adopt the phase-shifting algorithm to restore the wavefront information to be measured.The combination of shearing interferometry and synchronous phase-shifting technology can realize the absolute common optical path phase-shifting measurement of the phase to be measured and remove the influence of environmental vibration and air disturbance on the interferometry.The study of synchronous phaseshifting shearing interferometry is significant for detecting transmission wavefront pairs and the surface shape of optical elements.In the wavefront measurement,due to the influence of the surface error of the reference mirror,insufficient utilization of light energy,environmental vibration,and air disturbance on the interference measurement results,we propose a synchronous phase-shifting shearing interferometry method based on polarization grating splitting.This can achieve high-precision detection of transmission wavefront and reflection wavefront.Methods The proposed method is based on polarization grating beam splitting to achieve the wavefront test method of synchronous phase-shifting shearing interference,which can be utilized to test the transmission wavefront.The shearing module is a reflective transverse shearing structure composed of a polarization grating,a plane mirror,and a quarter wave plate.The polarization grating is a diffractive optical element that realizes sele

关 键 词：测量 波面检测 剪切干涉 同步移相 相位复原与重构算法 

分 类 号：O436[机械工程—光学工程]