在高功率激光系统中,激光束小尺度畸变波前探测是实现激光束中频段波前补偿与控制的重要前提。采用阵列菲涅耳波带片作为激光束波前传感的子孔径分割器,研究其聚焦性能,讨论了波带片的结构如阵列数目和阵列尺寸对波前探测精度的影响。仿真结果表明,选取合适的波带片结构参数可以使小尺度畸变波前的重构误差小于十分之一个波长。为了检测阵列菲涅耳波带片作为波前传感器检测波前畸变的性能,实现小尺度波前畸变检测的目的,构建了激光波前畸变检测光路系统。实验结果表明了阵列菲涅耳波带片检测波前畸变的可行性和准确性。
In high power laser system, small-scale phase distorted wavefront measurement is necessary to compensate and control the wavefront of laser beam with intermediate frequency. As wavefront sensor, array Fresnel zone plates split wavefront, and its focus characteristics were investigated. Also, influence of the structure of array Fresnel zone plates on wavefront reconstruction was discussed. Simulation results show that the error of wavefront reconstruction is less than one-tenth of wavelength with suitable optical parameters. The optical system for the measurement of distorted wavefront was built to investigate the sensing characteristics of array Fresnel zone plates. Experimental results prove the feasibility and effectiveness of the wavefront measurement.