对电寻址振幅型空间光调制器(SLM)在高功率激光系统中存在的问题进行了分析。理论分析了电寻址空间光调制器的黑栅效应对光束近场光束整形效果的影响, 提出了通过优化空间滤波器的小孔参数获得最佳整形效果的技术方案, 并计算了小孔滤波后的能量利用率。同时, 分析了液晶空间光调制器的开口率对光束整形的影响, 为了提升近场整形精度, 空间光调制器的开口率最好大于64%。研究了纯振幅型空间光调制器调制过程中引入的相位畸变, 从理论分析和实验验证两方面得出了附加相位分布图, 计算得出最大附加相位为0.135λ,对激光装置的影响在可接受范围之内。

The problems of the amplitude spatial light modulator(SLM) by electrical addressing in high power laser systems are analyzed. Firstly, the effect of the black gate of the SLM by electrical addressing on the near-field beam shaping is analyzed theoretically. The technical scheme of obtaining the best shaping effect by optimizing the aperture size of the spatial filter is proposed, and the energy efficiency of the filter is calculated. Meanwhile, the effect of liquid crystal SLM′s opening ratio on beam shaping is analyzed. In order to enhance the near-field shaping accuracy, the opening ratio of the SLM should be better than 64%. Finally, the phase distortion introduced by the pure amplitude spatial light modulator is studied. The additional phase is obtained from the theoretical analysis and experimental verification. The calculated maximum additional phase is 0.135λ, which means that the influence on the laser device is within acceptable range.