Mathematically modeling of target speed effect on nonlinearity in DTLMI-based nano-metrology system

Jones matrix computation is one of the widely used methods in nonlinearity calculation in laser interferometers. In this paper, the nonlinearity error in developed three-longitudinal mode heterodyne interferometer (DTLMI) has been mathematically modeled at various speeds, by using Jones matrix calculations. This review has been done despite the fact that simultaneously the main factors including non-ideal polarization of the laser beam and the non-ideal PBS produce nonlinearity. According to the results, it was found that although nonlinearity error is a pure sinusoid in low velocities, it isn't a single-sinus and increases in amplitude in high velocities. It was also observed that the effect of non-ideal PBS on nonlinearity error is less than that of non-ideal laser beam and frequency of nonlinearity error caused by it is twice more