PGC-Arctan demodulation method based on improved IKEF

Abstract

The proposed method is an improvement on the traditional PGC demodulation technique, specifically addressing the impact of carrier phase delay, modulation depth drift, and low-frequency ambient noise on phase demodulation accuracy in phase-modulated homodyne interferometers. It utilises an improved iterative extended Kalman filtering (IEKF) approach. The algorithm enhances the iterative updating process by incorporating a damping factor into the traditional IEKF. This enables optimal estimation and correction of the parameters of the PGC quadrature signals, resulting in reduced nonlinear error in the demodulation process. Additionally, the improved algorithm achieves higher demodulation accuracy. Simulation results demonstrate the method's effectiveness in eliminating nonlinear error in phase generation carrier.