High-speed manufacturing of highly regular femtosecond laser-induced periodic surface structures: physical origin of regularity


Nanostructured surfaces are of high interest for various scientific, biomedical and industrial applications. Numerous methods exist to produce nanostructured surfaces based on sputtering, chemical and plasma etching, chemical vapor deposition, self-assembly, nanoimprint, optical and physical lithography. Lithography techniques such as electron- and focused-ion- beam lithographies, and photolithography are most commonly used and provide high-precision nanostructuring. However, the lithography methods are multi-step, employing masks that makes them costly, time-consuming, mainly limited to semiconductor materials, and must be performed under vacuum or specific environment during processing.

Demonstration of high regularity of LIPSS obtained in this study on several metals. Arrows indicate directions of laser field polarization (E⟶) and laser beam scanning (v⟶). (a) Human-scale view of a stainless steel AISI 316 L sample covered with HR-LIPSS under ambient light conditions of the laboratory. Color arises from the diffraction of ambient light on the nanostructured material. (b–d) Respectively Secondary Electron Microscope (SEM) images of the Mo (effective pulse number N ~ 3.7, average fluence F = 0.69 J/cm2), Ti (N ~ 2.1, F = 0.59 J/cm2), and stainless steel (N ~ 2.1, F = 0.45 J/cm2) samples covered with HR-LIPSS. Steel comprises iron with 16.87% Cr and 10.05% Ni. Insets in Figs (b–d) show magnified views of corresponding images [2× in (b) and (c), 4× in (d)].