激光偏振干涉光路的非线性分析计算

Analysis and Calculation on Nonlinearity of the Laser Polarized Interferometer

偏振干涉光路两臂光程差的变化和合成干涉信号的相位变化，理论上具有线性关系，可以对引起光程差的任何微小量进行测量。实际上光路光学元件性能及调整并不理想，形成了二者的非线性关系。本文分析计算了各光学元件形成的非线性及这些元件综合形成的非线性，给出了适用于各种情况下的计算公式，并提出了光路的调整方法。

According to the theory,the change of optical path difference of a polarized interferometer is linear with the phase change of combined coherent signal,so it can be applied to measure infinitesimal quantity. But due to the applied optical elements and the bed adjustment being not ideal, the linearity will be damaged. Nonlinearities and their relation with above-mentioned effects are analysed and calculated in this paper. The equations applied to each situation and the correct adjustment method on laser polarized interferometer are also presented.