提出了一种用于单频激光干涉仪的非线性误差被动补偿方法。利用干涉仪中波片位置的在线预置，实现干涉仪偏振态的超前调整，补偿干涉仪中由偏振分光棱镜、消偏振分光棱镜以及波片的性能和位置非理想导致的非线性误差。构建干涉仪非线性误差在线检测装置进行实验研究。结果表明，通过被动补偿方法集成的干涉仪输出信号的交直流抑制比大于500，非线性正交相移m减小至0.003 rad(0.15 nm)。通过连续24 h的稳定性测量实验可知，参数m变化幅度在0.024 rad(1.21 nm)内，极大地抑制了干涉仪的非线性误差。

A passive nonlinear error compensation method is proposed for single-frequency laser interferometer. It is realized by changing the location of the wave plate in interferometer to adjust the polarization of the interferometer, which compensates the nonlinear error caused by the non-ideal performance and location of the polarized beam splitter, the depolarized beam splitter, the wave plates and other optical parts. A corresponding integrated interferometer nonlinear error on-line detection system is constructed. The experimental results show that the AC and DC output signal suppression ratio is greater than 500 and the nonlinear quadrate phase shift m is reduced to 0.003 rad (0.15 nm). Through stability measurement experiment in 24 h, m changes within the range of 0.024 rad (1.21 nm), which demonstrates the effectiveness of the method in greatly inhibiting nonlinearity.