Liquid vortexes and flows induced by femtosecond laser ablation in liquid governing formation of circular and crisscross LIPSS

• DOI: 10.29026/oea.2022.210066
• Publication Date: 2022-03-17T23:48:46Z
• Authors: Dongshi Zhang; ; Xinzhuo Li; Yao Fu; Qinghe Yao; Zhuguo Li; Koji Sugioka
• Keywords: Laser Ablation

Orientations of laser induced periodic surface structures (LIPSS) are usually considered to be governed by the polarization state. In this work, we unveil that fluid dynamics femtosecond (fs) ablation in liquid (fs-LAL) can easily break restriction produce irregular circular-LIPSS (CLIPPS) and crisscross-LIPSS (CCLIPSS). Fs silicon water shows formation diverse LIPSS depending on conditions. At a high power 700 mW (repetition rate 100 kHz, pulse duration 457 fs wavelength 1045 nm), single/twin CLIPSS produced at bottom macropores several microns diameter due strong vortexes occurrence vortex shedding effect. Theoretical simulations validate our speculation about with an ultrahigh static pressure, which induce microstructure trenches cracks sidewalls for fs-LAL Si tungsten (W) water, respectively. low 50 mW, weak produced, only give birth curved valleys grooves. Consequently, it is deduced plays crucial role macropores. Mountain-like microstructures complex cause CCLIPSS them. It believed presented work open up new possibilities diversify morphologies formed fs-LAL.