摘要：
The optical phase-locked loop (OPLL) technology is an effective-method to realize the phase coherent of laser beam. In consideration of the loop filter influence on OPLL, a new method was presented to obtain the optimized parameters of a second order passive loop filter. Firstly, a formula was deduced to design the parameters according to the definition of phase angle margin and mathematical model of open-loop transfer function. Based on MATLAB software, a parameter optimization algorithm was formulated. Secondly, in order to calculate the parameters of Raman laser optical phase-locked loop precisely, a experiment of Doppler-free absorption spectrum was designed to get the accurate gain parameter from the piezoelectric ceramic to feedback the laser. The overshoot and regulation time of unit step response were about 6.53% and 0.584 μs, respectively, in the systematic performance simulation of closed-loop optical phase-locked system. Finally, by using Simulink tools to establish models and simulating the optical phase-locked loop system module, the lasers′ phase was locked at a high speed with 2 μs. Therefore, the method of OPLL parameters optimization has turned out reasonable. In addition, certain guidelines can be given for the circuit devise of the optical phase-locked loop in engineering applications.%光学锁相环(Optical Phase-locked Loop,OPLL)技术是实现激光相位相干的有效方法.鉴于环路滤波器参数直接影响光学锁相环系统的整体性能,提出了一种二阶无源环路滤波器参数的优化方法.首先,根据相角裕度定义及系统开环传递函数的数学模型,推导出环路滤波器参数设计的公式,并设计了一种基于MATLAB的参数优化算法.然后,为精确地设计拉曼激光光学锁相环参数,设计了消多普勒饱和吸收谱实验,并对激光器的压电陶瓷端口反馈增益参数进行测量.在锁相环闭环控制系统性能仿真中,得到了单位阶跃响应的超调量为6.53%,调节时间为0.584 μs.最后,对拉曼激光光学锁相环各个模块进行Simulink建模并仿真,仿真结果表明锁相环能够实现对拉曼光相位锁定且锁定时间为2 μs,因此,验证了锁相环参数设计方法的正确性.在工程应用中,为光学锁相环的参数设计提供了重要参考价值.
