Ablation threshold dependence on pulse duration for copper

Abstract Laser ablation of Cu by short pulse laser (800 nm wavelength, 70 fs pulse duration, 0.01–28 J/cm2 fluence range) in air was studied. Three different ablation thresholds were distinguished in all metals. The ablation thresholds for Cu were found to be 0.018, 0.18, and 0.25 J/cm2. The lowest ablation threshold was of one order of magnitude lower than the one observed previously. In the fluence range of 0.018–0.18 J/cm2 the ablation rate was ≈0.01 nm per pulse. A dependence of the threshold on the pulse duration was demonstrated in the range of 70 fs–5 ps. As the laser pulse duration increased, the ablation threshold had the tendency to be higher.