Experimental research of laser-induced periodic surface structures in a typical liquid by a femtosecond laser

Abstract

A constant elastic alloy is a widely used material with a high elastic modulus and an excellent wave velocity consistency. Different morphologies on the constant elastic alloy surface are observed through femtosecond laser irradiation. When the laser average fluence is set to 0.58 J∕cm 2 and 200 laser pulses, with the increasing depth of distilled water, the period of the laser-induced periodic surface structures (LIPSS) becomes shorter accordingly. The higher the ethanol concentration is, the more spot-shaped structures will be formed among the surface structures when the depth of the coverage of ethanol is 2 mm. The period of the LIPSS reaches its maximum when the concentration of ethanol is 80%.

Formation of Periodic Surface Structures by Multipulse Femtosecond Laser Processing of Au-Coated Ni in Various Fluids

“…Up to now, the LIPSS formation on metals, alloys, semiconductors, and polymers has been mostly studied in air or vacuum, while only few reports exist regarding LIPSS generation in liquids, − as laser patterning in liquids is more complex. Particularly, on some metals LIPSS generation cannot always be achieved in liquids, due to the physiochemical properties of the solid or the liquid characteristics.…”

“…Simulation suggested the presence of Rayleigh-Taylor instability at the interface between the molten layer and supercritical water, trigger roughening, formation of morphological features, and self-organized structures. Sun and co-workers 34 studied femtosecond multipulse LIPSS on an elastic alloy (48.35% Fe and 42% Ni) in water and ethanol, and it was proposed that increased water depth decreased the LIPSS periodicity. In ethanol, the concentration played a role, and the highest periodicity was observed for 80% ethanol.…”