利用纯相位型液晶空间光调制器实现空心光束

为了提高激光系统的整体效率,需要将出射光强整形为空心分布。采用纯相位型液晶空间光调制器整形近高斯分布光强到空心分布。基于能量守恒定律和等光程原理,分析了纯相位型液晶空间光调制器光束整形系统,得出了整形系统所需的相位分布。采用衍射光学方法,数值模拟了整形效果,讨论了入射光束束腰半径和强度分布等因素对整形效果的影响。利用纯相位型液晶空间光调制器实验实现了空心光束,实验测得的转换效率大于99%。

Generation of dark hollow beam with phase only liquid crystal spatial light modulator

To improve the power efficiency of the laser system, it is necessary to transform Gaussian intensity distribution to dark hollow intensity distribution. The phase-only liquid crystal spatial light modulator (LC-SLM) has been used to transform a quasi-Gaussian beam to a dark hollow one. The phase distribution of the shaping system was derived according to the energy conservation law and the constant optical length principle. The influences of input beam waist and shape on shaping effect were discussed based on numerical simulation. The generation of the dark hollow beam has been realized experimentally with the phase-only LC-SLM, and the conversion efficiency was larger than 99%．