Abstract:In the traditional quantum phase tracking method, the output results are usually linearized, which has a strict limit on the local oscillator phase and signal phase, therefore, it is not applicable to the angle measurement by interferometry. In this paper, the quantum homodyne output is transformed and an iterative algorithm for maximum likelihood estimation is designed to realize the coherent state phase tracking. The Fisher information matrix is calculated to show that the proposed method can reach the quantum Cramer-Rao bound theoretically and has the best estimation.