基于激光散斑的固体折射率测量研究与改进  

Study and Improvement of Solid Refractive Index Measurement Based on Laser Speckle

作　　者：罗劲明 周柔燕 冯祖强 李俊豪 古家玮 许钦展 邓定南 Luo Jinming;Zhou Rouyan;Feng Zuqiang;Li Junhao;Gu Jiawei;Xu Qinzhan(College of Physics and Electronic Engineering,Jiaying University,Meizhou,Guangdong 514015,China)

机构地区：[1]嘉应学院物理与电子工程学院,广东梅州514015

出　　处：《应用激光》2022年第4期126-131,共6页Applied Laser

基　　金：广东省2018年高等教育教学改革项目(542);广东省基础与应用基础研究基金项目(2020A1515110283)。

摘　　要：根据透明固体介质的光学折射特点,对激光散斑测量透明固体折射率的传统方法进行了误差分析,并提出一种减小误差的改进方法:首先搭建像面散斑测量系统,透明固体则置于成像透镜和CCD相机之间,通过CCD相机先后采集待测透明固体垂直光轴放置时和偏转一定角度放置时的散斑图;然后利用数字图像相关法对采集到的两张散斑图进行相关处理,获得固体偏转前后的散斑面内偏移量;最后根据理论公式计算出其折射率。通过对比试验发现利用改进方法测量出来的结果误差小、精度高。Based on the optical refraction characteristics of transparent solid medium, the error analysis of the traditional method for measuring the refractive index of transparent solid using laser speckle is carried out, and an improved method to reduce the error is proposed. Firstly, an image speckle measurement system has been set up with the transparent solid placed between the imaging lens and CCD. After that, the two speckle patterns are collected by the CCD when the transparent solid is placed perpendicular to the optical axis and deflecting to a certain angle respectively. A speckle in-plane displacement can be obtained by processing the above two speckle patterns using the digital image correlation method. Finally, the refractive index of solid can be calculated based on the theoretical formula. According to the comparison experiments, the measurement results show that this improved method has smaller error and higher precision.

关 键 词：折射率 激光散斑 透明固体 数字图像相关 

分 类 号：O438.1[机械工程—光学工程]