提出一种采用光寻址液晶空间光调制器(LCSLM)作为二维激光分束和多光束偏转的无机械光束扫描系统, 可对平行入射的激光光束分束、偏转, 且只用1片LCSLM就能够对每一束光的方向和强度分别控制。采用G-S相位迭代算法来实现多光束可编程控制的相位模版的生成过程与仿真。先运用子孔径法在相位模版上生成所需要的相位分布作为初始值, 然后采用GS相位迭代过程优化相位分布, 使各子孔径中的相位分布渐次扩展到整个相位模版, 其间还提出了改进的GS相位迭代算法, 最后对计算所获相位分布进行反演模拟。结果表明: 所提出的多光束二维偏转的算法能够满足应用需要, 且改进的GS相位迭代算法能提高多光束偏转的衍射效率, 优化光束光斑强度, 降低光束的均方根误差。

A non mechanical beam steering system with light addressed liquid crystal spatial light modulator(LCSLM) is proposed and designed to resolve the problem of two-dimensional laser beam splitting and muti-beam deflection, which can control the direction and intensity of each beam separately with only one LCSLM. The generation process and simulation of the phase template of multi-beam programmable control is realized by G-S phase iterative algorithm. Firstly, the sub-aperture method is used to generate the required phase distribution as the initial value. Then, the G-S phase iterative algorithm is used to optimize the phase distribution, so that the phase distribution in each sub-aperture is gradually extended to the entire phase template. An improved G-S phase iterative algorithm is proposed. Finally, the inverse phase simulation of the calculated phase distribution is performed. The simulation results show that the proposed multi-beam two-dimensional deflection algorithm can meet the application needs, and the diffraction efficiency of multiple beams is enhanced and the root mean square error of the beam is reduced.