Laser-induced ablation of tantalum in a wide range of pulse durations

Abstract

We present data and analysis of the laser-induced ablation of pure tantalum (Ta, Z= 73). We have identified different physical regimes using a wide range of laser pulse durations. A comparison of the influence of strongly varying laser pulse parameters on high-Z materials is presented. The crater depth caused by three different laser systems of pulse duration Δτ1=5ns and wavelength λ1=1064nm, Δτ2=35ps, λ2=355nm and Δτ3=8.5fs, λ3=790nm are analyzed via confocal microscopy as a function of laser fluence and intensity. The minimum laser fluence needed for ablation, called threshold fluence, decreases with shorter pulse duration from 1.10J/cm2 for the nanosecond laser to 0.17J/cm2 for the femtosecond laser.