Plasmonic nature of periodic surface structures following single laser pulse irradiation

Understanding the mechanisms and controlling the possibilities of surface nanostructuring is of crucial interest from fundamental and practical perspectives. Here we report a direct experimental observation of laser-induced periodic surface structures (LIPSS) formed near a predesigned gold step edge following single-pulse femtosecond laser irradiation. A hybrid atomistic-continuum model fully supports experimental observations. We identify two key components of single-pulse LIPSS formation: excitation of surface plasmon polaritons and material reorganization. Our results lay the foundation towards simple and efficient single laser pulse micromachining.