Measurement of ultrashort laser ablation of four metals (Al, Cu, Ni, W) in single pulse regime

Abstract: We provide measurements of ablation of four post-transition and transition metals (aluminum, copper, nickel and tungsten) irradiated by single 800 nm laser pulses, in ultrashort regime from 100 fs pulse duration down to 15 fs covering a temporal range little explored yet. For each metal and pulse duration tested, we measure its ablation characteristics (depth and diameter) as a function of incident energy allowing us to determine its laser-induced ablation threshold and ablation rate in single-shot regime. For all metals studied, we observe constant ablation threshold fluence as a function of pulse duration extending this scaling law to pulse duration of few-optical-cycles. We also provide evidence of the interest of adjusting the incident fluence to maximize the energy specific ablation depth but also of the absence of any peculiar advantage related to the use of extremely short pulse duration for ablation purposes. Those informative and detailed ablation data have been obtained in single pulse regime and in air ambiance. They can serve as rewarding feedback for further establishing smart strategy for femtosecond laser micromachining and laser damage handling of metallic and metal-based components as well as for enhancing accuracy of modeling of femtosecond laser interaction with metals in ultrashort regime.