Its error source and the way of changing are analyzed, especially for two factors, i.e., elliptic polarization of laser and installation error of Wollaston prism, which can cause frequency mixing errors in common path heterodyne interferometer.

• 重点分析了在共光路外差干涉仪中由激光光源的椭圆偏振化和Wolaston棱镜的安装方位角引起的频率混叠误差的大小及变化规律。