超精表面缺陷检测的光学混频误差分析  

Error Analysis of Optical Frequency Mixing on Detecting Device for Superfinish Surface Scratch

作　　者：林浩山[1] 陈举科[1] 李玉和[2] 李庆祥[2] 潘福东[1] 王力虎[1] 

机构地区：[1]广西师范大学物理科学与技术学院,广西桂林541004 [2]清华大学精密测试技术及仪器国家重点实验室,北京100084

出　　处：《激光与光电子学进展》2015年第2期159-165,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61362035;51275259)

摘　　要：双频激光外差干涉法与扫描探针相结合的超精表面缺陷检测系统具有很高的分辨率。但系统光源和光学器件的各种误差因素会产生非线性混频误差,影响系统精确测量。利用琼斯矩阵分析了同时存在激光光源椭圆偏振化和方位角误差以及光学器件相位延迟和偏振泄漏等综合因素引起的偏振态变化,并由此研究了它们频率混叠产生的非线性误差。结果表明,由各种误差因素引起的非线性混频误差呈正弦规律变化,激光光源非理想和偏振分光镜对位移测量误差影响较大而1/4波片的影响较小。同时,结合计算结果对系统提出了减少非线性误差的方法措施。A novel method with high resolution has been proposed which is based on heterodyne interferometry and scanning probe to get the measurement values of superfinish surface scratch. But the optical nonlinear errors affect the measurement precision of the system. We adopt the Jones matrix to analyze the change of elliptic polarization caused by the composite error factors, which are polarization ellipticity and installation orientation error of laser source, phase retardation of quarter- wave plate and polarization leakage of polarization beam splitter. The measurement errors of frequency mixing about these elliptic polarization beams arriving at the photodiode detector are studied by vector theory. The results show that the measurement errors are periodic errors, and they are more affected by nonideal laser and polarization beam splitter. Also, the methods of reducing nonlinear error according to the numerical results in the system are suggested.

关 键 词：测量 外差干涉 偏振光 琼斯矩阵 频率混叠 非线性误差 

分 类 号：TH744.3[机械工程—光学工程]