Unraveling the formation dynamics of metallic femtosecond laser induced periodic surface structures
Unraveling the formation dynamics of metallic femtosecond laser induced periodic surface structures
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DOI：
10.1016/j.optlastec.2023.110410
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发表时间：
2023-08
期刊：
影响因子：
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通讯作者：
L. K. Khorashad;A. Reicks;A. Erickson;J. Shield;D. Alexander;A. Laraoui;G. Gogos;C. Zuhlke;C. Argyropoulos
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文献类型：
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作者：
L. K. Khorashad;A. Reicks;A. Erickson;J. Shield;D. Alexander;A. Laraoui;G. Gogos;C. Zuhlke;C. Argyropoulos
飞秒激光表面处理（FLSP）是一种新兴的加工技术，可以有效地控制包括金属在内的多种材料的表面形貌。然而，对FLSP地层动力学的理论理解并不是一项简单的任务，因为它涉及各种物理过程（电磁、热、流体动力学）的相互作用，相对而言仍未被探索。在这项工作中，我们解决了这一问题，并提出了与低通量FLSP相关的严格理论结果，这些结果与专注于不锈钢激光诱导周期性表面结构（LIPSS）形成动力学的实验结果精确匹配。更具体地说，从理论上和实验上研究了LIPSS沟槽的地形和最大深度作为激光脉冲数的函数。此外，使用原子力显微镜（AFM）进行了精确的LIPSS形态测量。所提出的综合模拟研究基于双温模型（TTM）非平衡热模拟与流体动力学计算相结合，以捕获FLSP过程中发生的熔化金属相。我们严格的模拟结果与AFM测量结果非常吻合。本文提出的低通量飞秒激光脉冲下FLSP模型的理论框架将有利于LIPSS在金属表面的各种新兴应用，如冷却高功率激光二极管和控制金属的热发射或吸收。
Femtosecond laser surface processing (FLSP) is an emerging fabrication technique to efficiently control the surface morphology of many types of materials including metals. However, the theoretical understanding of the FLSP formation dynamics is not a trivial task, since it involves the interaction of various physical processes (electromagnetic, thermal, fluid dynamics) and remains relatively unexplored. In this work, we tackle this problem and present rigorous theoretical results relevant to low-fluence FLSP that accurately match the outcomes of an experimental campaign focused on the formation dynamics of laser induced periodic surface structures (LIPSS) on stainless steel. More specifically, the topography and maximum depth of LIPSS trenches are theoretically and experimentally investigated as a function of the number of laser pulses. Moreover, precise LIPSS morphology measurements are performed using atomic force microscopy (AFM). The proposed comprehensive simulation study is based on two-temperature model (TTM) non-equilibrium thermal simulations coupled with fluid dynamic computations to capture the melting metal phase occurring during FLSP. Our rigorous simulation results are found to be in excellent agreement with the AFM measurements. The presented theoretical framework to model FLSP under low-fluence femtosecond laser pulses will be beneficial to various emerging applications of LIPSS on metallic surfaces, such as cooling high-powered laser diodes and controlling the thermal emission or absorption of metals.