Polarization-dependent elliptical crater morphologies formed on a silicon surface by single-shot femtosecond laser ablation.
Polarization-dependent elliptical crater morphologies formed on a silicon surface by single-shot femtosecond laser ablation.
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DOI：
10.1364/ao.53.006742
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发表时间：
2014-10
期刊：
影响因子：
1.9
通讯作者：
Xu Ji;Lan Jiang;Xiaowei Li;W. Han;Yang Liu;Qiang Huang;Y. Lu
中科院分区：
文献类型：
--
作者：
Xu Ji;Lan Jiang;Xiaowei Li;W. Han;Yang Liu;Qiang Huang;Y. Lu
利用单次飞秒激光对硅表面椭圆形坑的形成进行了全面的研究。结果表明，烧蚀坑沿极化方向的长轴沿着伸长，而烧蚀坑的取向与极化方向平行。随着注量的增加，烧蚀面积逐渐增大，陨坑的形态也由椭圆形逐渐演变为近似圆形。通过基于时域有限差分技术的数值模拟，揭示了潜在的物理机制。研究表明，初始形成的坑或表面缺陷导致了硅表面电场的重新分布，对椭圆形坑的形成起着至关重要的作用。另外，场强沿沿着入射激光偏振方向增强，这决定了椭圆形凹坑的取向。
Formation of the elliptical-shaped craters on a silicon surface is investigated comprehensively using a single shot of a femtosecond laser. It is observed that the ablation craters are elongated along the major axis of the polarization direction, while their orientation is parallel to the polarization direction. The ablation area grows and the morphology of the craters evolves from an ellipse to nearly a circle with increasing fluence. The underlying physical mechanism is revealed through numerical simulations that are based on the finite-difference time-domain technique. It is suggested that the initially formed craters or surface defects lead to the redistribution of the electric field on the silicon surface, which plays a crucial role in the creation of the elliptical-shaped craters. In addition, the field intensity becomes enhanced along the incident laser polarization direction, which determines the elliptical crater orientations.