零差激光干涉仪的大范围位移测量与精度分析

Large-range Displacement Measurement and Accuracy Analysis of Homodyne Laser Interferometer

研制了一种实用性强的零差激光干涉仪,采用立方角锥棱镜代替平面反射镜,克服了传统激光干涉仪光路调节困难的问题,并将其应用到大量程的位移测量中。研究了该改进型零差激光干涉仪的位移测量原理及信号处理方法。实验中,使用PI公司高精度的商用导轨来标定测量结果,通过比较测量结果来验证干涉仪的性能。实验结果表明,在百毫米级大范围位移测量中该干涉仪的位移测量精度可以达到小于0.7μm。对测量过程中各种可能的误差来源进行了详细的分析,分析结果与实验相符。

A practical homodyne laser interferometer which used cubic corner reflector instead of plane mirror for measuring large-scale displacement was developed in view of the difficulties in adjusting the light path.The displacement measurement theory and the signal processing method were proposed.Experimentally,PI＇s high-precision commercial electric displacement platform was included in the displacement measurement to evaluate the performance of the interferometer during the experiment.Experimental results show that the improved interferometer＇s displacement measurement precision can reach less than 0.7μm in the hundred mm large-scale displacement measuring process.The error source in the measuring process was analyzed,and the results obtained were conformed to that of the experiments.