Tailored laser beam shaping for efficient and accurate microstructuring
Tailored laser beam shaping for efficient and accurate microstructuring
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DOI：
10.1007/s00339-017-1530-0
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发表时间：
2018-02-01
影响因子：
2.7
通讯作者：
Schmidt, M.
中科院分区：
文献类型：
--
作者：
Haefner, T.;Strauss, J.;Schmidt, M.
随着高功率USP激光系统的发展，利用超短脉冲（USP）激光进行大面积高材料去除率的加工成为焦点。然而，目前高速率生产的瓶颈是由缓慢和低效的光束操纵给出的。一方面，相对于高脉冲重复率的慢光束偏转导致热积累和屏蔽效应，另一方面，由于高斯强度分布，常规聚焦不能提供最佳的注量。本文着重研究了硅基液晶空间光调制和声光光束整形两种激光光束的动态整形方法。讨论了动态激光束整形在USP激光材料加工中的优点和局限性，以及减少散斑影响的方法。此外，光学引起的像差的散斑特性的影响进行了评估。激光材料加工的结果与模拟和测量的光束质量相关的结构质量。实验和分析研究表明，实现均匀的微结构所需的替代全息图的数量有一定的注量依赖性。
Large-area processing with high material removal rates by ultrashort pulsed (USP) lasers is coming into focus by the development of high-power USP laser systems. However, currently the bottleneck for high-rate production is given by slow and inefficient beam manipulation. On the one hand, slow beam deflection with regard to high pulse repetition rates leads to heat accumulation and shielding effects, on the other hand, a conventional focus cannot provide the optimum fluence due to the Gaussian intensity profile. In this paper, we emphasize on two approaches of dynamic laser beam shaping with liquid crystal on silicon spatial light modulation and acousto-optic beam shaping. Advantages and limitations of dynamic laser beam shaping with regard to USP laser material processing and methods for reducing the influence of speckle are discussed. Additionally, the influence of optics induced aberrations on speckle characteristics is evaluated. Laser material processing results are presented correlating the achieved structure quality with the simulated and measured beam quality. Experimental and analytical investigations show a certain fluence dependence of the necessary number of alternative holograms to realize homogeneous microstructures.