期刊
OPTICS AND LASERS IN ENGINEERING
卷 165, 期 -, 页码 -出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.optlaseng.2023.107537
关键词
LCoS SLM; Phase-only beam shaping; Speckle averaging; Ultrashort pulsed laser materials processing
类别
A phase-only spatial light modulator (SLM) is a powerful tool used to shape arbitrary intensity distributions, but it is limited in controlling the full complex light field, resulting in the presence of speckle patterns. We propose a method using liquid crystal on silicon SLM and a single phase mask to achieve near-perfect and highly efficient speckle averaging. The method involves high-speed scanning of the laser beam using a galvanometer scanner and compensating for the scanning movement to maintain a static target image.
A phase-only spatial light modulator (SLM) is a powerful tool to shape arbitrary intensity distributions and finds application in various research fields and industry. However, since phase-only beam shaping cannot control the full complex light field, a speckle pattern overlays the shaped target intensity and strongly impairs the result. Several methods have been developed to diminish speckle noise, all of which have their advantages and disad-vantages. Usually they offer a compromise between quality and efficiency. We present a method for phase-only beam shaping which achieves near-perfect and highly efficient speckle averaging with a liquid crystal on silicon SLM based on a single phase mask. A galvanometer scanner scans the laser beam over the active area of the SLM to achieve high-speed averaging. The applied angle resulting from the scanning movement is compensated by a proper optical setup to maintain a static target image with speckle averaging out. As an additional benefit of the scanning movement, artifacts from light not diffracted by the SLM disappear in the target plane. The setup is designed for high-energy laser beams as intermediate foci are avoided at all optical components. Besides optical averaging on camera images, we validate our method with ablation experiments where we make a profound anal-ysis of the involved system parameters and the achieved quality. Thereby, it becomes apparent that the proposed method not only stands out by the high-quality results but also by its simplicity in implementation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据