Pump-probe Microscopy Investigations on Fs-laser Ablation of Thin Ta2O5/Pt Layer Systems

A femtosecond laser is used for selective structuring of biocompatible sensorchips consisting of a Ta 2 O 5 /Pt layer system on glass substrate. It was observed, that for low fluences the Ta 2 O 5 can be selectively lifted-off from the Pt, while high fluences enable a removal of both layers. The underlying physical effects are investigated by pump-probe microscopy allowing the observation of the whole ablation process ranging temporally from femtoseconds to microseconds. Results show the formation of a gas-liquid mixture at 3 ps, causing the Ta 2 O 5 to bulge after some ns. The Ta 2 O 5 is disrupted in small particles after 50 ns.