Nano-ablation of silica by plasmonic surface wave at low fluence.

Formation of ripples by ablation of surfaces of laser-irradiated materials is an example of ultrafast energy delivery. Herein, we report on fs-laser optical imprinting of periodic nano-grooves on silica substrate at only 25% of the laser ablation threshold via an interface plasmonic light localization at the ZnS film (top) interface with silica (bottom) by plasmonic surface wave. The nano-grooves were formed throughout ZnS with the same period and orientation imprinted onto the underlying silica. Based on a detailed account of the multi-photon and avalanche ionization using the Drude model, laser-induced plasmonic ablation describes quantitatively the energy deposition from the top ZnS to the substrate of silica.