MEMS显微干涉测量系统中相位提取算法的选择与分析

Choice and Analysis of Phase Extracting Algorithm in the MEMS Microscopic Interferometric Testing System

描述了一种基于相移显微干涉术的MEMS测试方法,达到了纳米级分辨力.从理论上分析了4种常用相移算法对测量过程主要噪声(相移器的移相误差和探测器的非线性响应误差)的抑制作用,并选定了适合本系统的Hariharan算法.通过对经过美国国家标准研究院(NIST)认证的一个台阶高度的测量,验证了各种算法的测量精度,说明Hariharan算法对噪声有更强的抑制作用,其测量重复性在亚纳米量级.

A micro electro-mechanical system（MEMS） testing method was presented based on phase shifting microscopic interferometry with nanoscale resolution. Response of four common phase shifting algorithms to the main error sources（the phase shifting errors of the phase shifter and the non-linear errors of the detector） were analyzed theoretically. Hariharan algorithm was chosen as the data processing method that is suitable for the system. Experiments on a step height calibrated by NIST give the accuracy of all algorithms, and the results show that Hariharan algorithm is more restrictive to the main error resources than the other algorithms and its measuring repeatability is around sub-nanometer.