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 nonlinearitycalculation in laser interferometers. In this paper, the nonlinearity error in developedthree-longitudinal mode heterodyne interferometer (DTLMI) has been mathematicallymodeled at various speeds, by using Jones matrix calculations. This review has been donedespite the fact that simultaneously the main factors including non-ideal polarization ofthe laser beam and the non-ideal PBS produce nonlinearity. According to the results, itwas found that although nonlinearity error is a pure sinusoid in low velocities, it isn't asingle-sinus and increases in amplitude in high velocities. It was also observed that theeffect of non-ideal PBS on nonlinearity error is less than that of non-ideal laser beam andfrequency of nonlinearity error caused by it is twice more.