Generation mechanisms of laser-induced periodic nanostructures on surfaces of microgrooves

Abstract

Functional surfaces with hierarchical micro-/nanostructures play a vital role in improving performances in emerging fields over the past decades. In this work, we propose a hybrid manufacturing method for efficiently fabricating hierarchical nanotextured microgrooves by combining fly cutting and femtosecond laser nanopatterning. Nanostructures, including nanogratings and nanoholes, can be uniformly generated in a V-shaped groove by controlling laser polarization. We experimentally study the influence of the laser parameters (laser fluence and effective pulse number) to investigate the morphological evolution of nanostructures in the V-shaped groove under laser irradiation. By theoretical calculations and analyses, we find that the interference between the incident and reflected laser is helpful for ablating the nanogratings. In addition, this interference can also couple with the laser-SPPs (surface plasmon polaritons) interference and form nanoholes. The results enrich the diversity of achievable laser-induced periodic surface structures on complex surfaces and provide a new way to efficiently fabricate large-area hierarchical micro-/nanostructures at low cost.