Towards rapid large-scale LIPSS fabrication by 4-beam ps DLIP

Abstract

Using four beam direct laser interference patterning (DLIP) Laser Induced Periodic Surface Structures (LIPSS, ripples) are simultaneously generated on surface of AISI 316L steel in more than thousands of spots at once. Both low-spatial frequency LIPSS (LSFL) and high-spatial frequency LIPSS (HFSL) are possible to fabricate with optimized parameters of 1030 nm, 1.7 ps PERLA laser system, developed and operated at HiLASE center. A novel large-beam DLIP technique applied for the redistribution of initial laser energy per pulse results in fabrication of ~1520 spots with LSFL in 50 ms and ~1016 spots with HSFL in 5 ms, thus significantly improving the productivity in comparison with the single beam approach. Efficient production of LIPSS structures over large area, required for applications such as a production of security diffractive elements and surfaces with superhydrophobic properties is also demonstrated. Possible steps for further increase of processing speed are discussed.