The formation of self-assembled laser induced periodic surface structures (LIPSSs) after ultrashort pulsed laser ablation is still a matter of controversy in the literature. There is agreement that at least two different physical driving forces lead to ripples with distinguishable spatial periodicity. High spatial frequency LIPSSs with periodicity well below the incident wavelength are discriminated from low spatial frequency LIPSSs (LSFLs) revealing longer periodic structures. In general, both types of LIPSS appear after multipulse irradiation with the linear polarization direction on all material classes from metals to dielectrics. However, single-pulse induced LSFLs at 540 ± 35 nm periodicity with subpicosecond pulse are observed at linelike surface defects, e.g., scratches and grain boundaries. Depending on the difference in orientation between the electric field vector and the scratch direction, LIPSSs evolve upon ablation with 515 nm and 1 ps pulses near the threshold. This corroborates the theory proposed by Sipe et al. [Phys. Rev. B 27, 1141–1154 (1983)], where the impinging electromagnetic wave interacts with a collectively excited surface electron wave of the respective material at a surface defect. The observations on oxygenfree pure copper, zirconia, and a stainless steel substrate are discussed. Moreover, LSFLs generated with circular polarization at defects after single pulse ablation of wide bandgap zirconia ceramic are presented. In application, this phenomena affects the attainable surface quality, where LSFLs appear at defects such as scratches, grain boundaries, and, generally, material inhomogeneity. The absorptivity and ablation characteristic change leading to an altered material-laser interaction at the surface. This could be the root cause of conelike protrusion structures observed on stainless steel.

中文翻译：

---

观察单次超短激光脉冲在线状缺陷上产生的周期性表面结构

超短脉冲激光烧蚀后自组装激光诱导周期性表面结构（LIPSSs）的形成在文献中仍然存在争议。一致认为至少有两种不同的物理驱动力会导致具有可区分空间周期性的涟漪。周期性远低于入射波长的高空间频率 LIPSS 与显示更长周期结构的低空间频率 LIPSS (LSFL) 不同。通常，这两种类型的 LIPSS 在从金属到电介质的所有材料类别上以线性极化方向进行多脉冲照射后都会出现。然而，在 540 ± 35 nm 周期性和亚皮秒脉冲的单脉冲诱导 LSFL 在线状表面缺陷处观察到，例如划痕和晶界。根据电场矢量和划痕方向之间的方向差异，LIPSSs 在消融时演变为 515 nm 和阈值附近的 1 ps 脉冲。这证实了 Sipe 等人提出的理论。[物理。Rev. B 27, 1141–1154 (1983)]，其中撞击电磁波与表面缺陷处相应材料的集体激发表面电子波相互作用。讨论了对无氧纯铜、氧化锆和不锈钢基材的观察。此外，还介绍了宽带隙氧化锆陶瓷单脉冲烧蚀后在缺陷处用圆极化产生的 LSFL。在应用中，这种现象会影响可达到的表面质量，其中 LSFL 出现在缺陷处，例如划痕、晶界，以及通常的材料不均匀性。吸收率和烧蚀特性的变化导致表面的材料-激光相互作用发生改变。这可能是在不锈钢上观察到的锥形突起结构的根本原因。