波片对偏振激光干涉仪非线性误差的影响

利用琼斯矩阵理论,研究了基于偏振移相技术的激光干涉仪中1/4波片和1/2波片的非理想因素导致非线性误差的产生机理和变化规律.理论研究表明:在导致波片处于非理想状态的各个因素中,干涉仪中两个1/4波片的差模延迟角误差Δεq所产生的恒定偏置误差和接收装置中1/4波片的延迟角误差εq3所引起的一次谐波非线性误差,是组成干涉仪非线性误差的最主要的两个部分;波片各种误差源非理想因素导致的非线性误差在小误差情况下经线性叠加后由干涉仪最终输出.

Effects of Wave Plate on Nonlinear Errors in Polarization Laser Interferometer

The mechanism of nonlinear errors′ appearance and the varying rule of nonlinear errors in laser interferometer based on polarized phase-shift technology, which is caused by nonideal factors of 1/4 wave plate and 1/2 wave plate, were studied by use of Jones matrix theory. It provided error compensation for laser interferometer in nanometer level measurement with theoretical foundation. Theoretical studies indicate that among the factors which make the state of wave plate to be nonideal, the invariable offset error caused by difference delay angle error Δεq of two 1/4 wave plates in interferometer, and the nonlinear error of the first order harmonic wave caused by delay angle error εq3 of 1/4 wave plate in receiver, are the two most primary components of interferometer′s nonlinear errors. Nonlinear errors caused by nonideal factors and various errors′ source of wave plate are finally to be an output of interferometer by adding up linearly.