一种重构高功率激光束波前的方法

A Novel Method to Reconstruct the Wavefront of High Power Laser Beam

介绍一种对“星光”１０１２Ｗ高功率激光器的波前相位进行重构测量的研究方法．实验中，对高功率激光束经过孔阵列相位传感器在像纸上烧蚀成的光斑阵列进行图像处理，测定各光斑光强中心及相对位移，再由理论分析得到实用的迭代算法公式，重构出高功率激光束波前．此方法用计算机软件实现了常规哈特曼－沙克（Ｈａｒｔｍａｎｎ－Ｓｈａｃｋ）传感器中子透镜阵列的子光束聚焦过程，可直接测量高功率大光束直径激光束的波前．文中给出了这种重构波前方法的基本原理和实用的重构公式．利用此方法在“星光”高功率激光器上进行了重构波前实验，最大可测激光束直径为２００ｍｍ，波前重构分辨率约为λ／５．

A novel method is presented to reconstruct the wavefront with phase distortion in STRALIGHT ⅠⅠ 10 12 W high power laser apparatus by means of computer image processing. In experiments, the image processing of optical spots fired on photograph by high power laser beams through a plate with hole array. The iteration formula group was deduced to apply in the experiments. Each center of intensitv of optical spots and relative shift were measured, and phase wavefront of high power laser was reconstructed in iteration. Computer software made the focusing procedure of small optical beams in hole array instead of which in sub lens array of normal Hartmann Shack sensor. The method can be used to measure directly the high power laser beam with large diameter. The principle and the formula of the reconstruction are described. The method has been used in the experiments of the high power laser apparatus STARLIGHT ⅠⅠ. The maximum diameter measured is 200 mm,and the resolving power of wavefront reconstruction is about λ/5.