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

Abstract

AbstractWe present data and analysis of the laser-induced ablation of pure tantalum (Ta, $$Z=73$$ 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 $${\varDelta }\tau _1=5\,\mathrm {ns}$$ Δ τ 1 = 5 ns and wavelength $$\lambda _1=1064\,\mathrm {nm}$$ λ 1 = 1064 nm , $${\varDelta }\tau _2=35\,\mathrm {ps}$$ Δ τ 2 = 35 ps , $$\lambda _2=355\,\mathrm {nm}$$ λ 2 = 355 nm and $${\varDelta }\tau _3=8.5\,\mathrm {fs}$$ Δ τ 3 = 8.5 fs , $$\lambda _3=790\,\mathrm {nm}$$ λ 3 = 790 nm 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 $$1.10\,\mathrm {J/cm}^2$$ 1.10 J / cm 2 for the nanosecond laser to $$0.17\,\mathrm {J/cm}^2$$ 0.17 J / cm 2 for the femtosecond laser.