Asymmetry of Pound–Drever–Hall error signal induced by spatial modes coherence

we revise the theoretical expression of the PDH error signal according to the theory of coherence between the higher-order modes and the fundamental mode and give the analytical equation of the asymmetry of the PDH error signal. The validation of this theory has been provided by both numerical simulation and experiment.我们依据高阶模式与基模之间的相干性理论，修正了PDH误差信号（PDH error signal）的理论表达式，并推导得到了PDH误差信号不对称性的解析方程。该理论的有效性已通过数值模拟与实验共同验证。