基于空间光调制器的飞秒并行加工方法研究

Parallel processing with femtosecond laser using spatial light modulator

针对飞秒激光微加工中能量利用率和加工效率低的问题,提出一种基于空间光调制器的飞秒并行加工方法。在讨论衍射光栅入射角与衍射角关系的基础上,分析了叠加多个衍射光栅产生多光束的原理,运用GS算法对目标多光束进行优化并计算出相应的相位全息图,将该全息图加载到空间光调制器中获得了多光束。采用脉宽100fs、波长800nm的飞秒激光,进行聚焦PMMA样品内部的并行加工实验,观察到PMMA上多点组合的"一"和"工"字型,得到了光束能量均匀的图形。实验结果论证了该方法对于多光束并行加工控制的有效性。

In order to solve the problems of low energy utilization and low efficiency in femtosecond laser micromachining,a new method of femtosecond parallel processing based on spatial light modulator（SLM）was proposed.Based on the discussion of the relationship between incident angle and diffraction angle,the principle of superposition of multiple diffraction gratings was analyzed.Multiple beams were generated by loading the phase holograms calculated using gerchberg and saxton（GS）algorithm on the SLM.The parallel femtosecond laser beam with the pulse width of 100 fs and the wavelength of 800 nm was focused inside a polymethyl methacrylate（PMMA）sample,uniform multi-point patterns of＂一＂and＂工＂were observed.Experimental results show that it is an effective method for controlling multi-beam parallel processing.