Relations between nonlinearity and PBS in heterodyne Michelson interferometer with different optical structures

Heterodyne interferometer is an important optical instrument which is widely used in the precision measurement and positioning. As the important optical part, the polarized beam splitter (PBS) divides a polarized laser beam with the random direction into two orthogonal linear polarized beams. This paper studies the relation between the nonlinearity errors and PBS in two typical heterodyne Michelson interferometer structures and proves that the nonlinearity errors from the nonideal PBS are related with the optical structures of interferometer. Moreover, the details on the mathematical analysis and the simulations for the relations are demonstrated in this paper.