Center for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300, Vilnius, Lithuania.
Sci Rep. 2018 Nov 26;8(1):17376. doi: 10.1038/s41598-018-35604-z.
Ultra-short laser pulses are frequently used for material removal (ablation) in science, technology and medicine. However, the laser energy is often used inefficiently, thus, leading to low ablation rates. For the efficient ablation of a rectangular shaped cavity, the numerous process parameters such as scanning speed, distance between scanned lines, and spot size on the sample, have to be optimized. Therefore, finding the optimal set of process parameters is always a time-demanding and challenging task. Clear theoretical understanding of the influence of the process parameters on the material removal rate can improve the efficiency of laser energy utilization and enhance the ablation rate. In this work, a new model of rectangular cavity ablation is introduced. The model takes into account the decrease in ablation threshold, as well as saturation of the ablation depth with increasing number of pulses per spot. Scanning electron microscopy and the stylus profilometry were employed to characterize the ablated depth and evaluate the material removal rate. The numerical modelling showed a good agreement with the experimental results. High speed mimicking of bio-inspired functional surfaces by laser irradiation has been demonstrated.
超短激光脉冲常用于科学、技术和医学中的材料去除（烧蚀）。然而，激光能量往往使用效率不高，因此导致烧蚀速率低。为了高效地烧蚀出矩形型腔，必须对扫描速度、扫描线之间的距离以及样品上的光斑尺寸等众多工艺参数进行优化。因此，寻找最佳的工艺参数组合始终是一项耗时且具有挑战性的任务。深入了解工艺参数对材料去除率的影响，可以提高激光能量的利用效率，提高烧蚀速率。在这项工作中，引入了一种新的矩形型腔烧蚀模型。该模型考虑了烧蚀阈值的降低，以及随着每个光斑的脉冲数增加，烧蚀深度的饱和。采用扫描电子显微镜和触针轮廓仪对烧蚀深度进行了表征，并评估了材料去除率。数值模拟与实验结果吻合较好。通过激光辐照实现了对仿生功能表面的高速模拟。
