Adaptive optics solution to improve laser-induced periodic surface structuring (LIPSS)

Abstract

Laser-induced periodic surface structures (LIPSS) are normally created to induce peculiar surface properties but, despite their interesting properties, LIPSS generation has a main drawback which is its low throughput rate. This limits applications on large surfaces. In this work, adaptive optics is used to increase productivity, and processing tests are conducted on stainless steel and nickel-titanium alloy as examples of surfaces for biomedical and luxury applications.The use of a deformable mirror to dynamically control the wavefront and the spatial energy distribution at the focal point of a picosecond laser is introduced and discussed.The shape of the focused beam is theoretically predicted and experimentally investigated with a sub-micron, highresolution beam profiler. The shape obtained in the focus can be dynamically controlled at the level of the single vector to be scanned. Results confirm that this method can overcome the aforementioned limitations and significantly increase the throughput rate in LIPSS generation.