Control of short-pulsed laser induced periodic surface structures with machining - Picosecond laser micro/nanotexturing with ultraprecision cutting

Short-pulsed laser in the fabrication of fine periodic surface structures (hereinafter, referred to as LIPSS: laser induced periodic surface structures) has been studied to reduce friction, improve control of wettability and improve bioaffinity. While it has low cost and stable irradiation compared with the ultrashort-pulsed laser traditionally used, it is difficult to control the fabrication of LIPSS using the short-pulsed laser because of its lower peak fluence than the ultrashort-pulsed laser and the unclarified principle. Optimizing the surface shape before laser irradiation may make it easier to control fabrication using short-pulsed laser since it has been reported that LIPSS is fabricated due to surface plasmons induced by plasma waves after altering the surface roughness during laser irradiation. The proposed method involves cutting the surface to assist with the short-pulsed laser for the control LIPSS: the surface of the workpiece is irradiated after straight microgrooves are fabricated by ultraprecision cutting. The experimental results showed that microgrooves made straight LIPSS with a high aspect ratio and also expanded the effective fluence range of experimental conditions when fabricating LIPSS. The new method was shown to control LIPSS effectively, and highlights the importance of the surface shape before laser irradiation for LIPSS fabrication.