Laser-induced back-ablation of aluminum thin films using picosecond laser pulses

A study of Laser-Induced Back-Ablation of Aluminum thin film targets with picosecond laser pulses is reported. Ablated plume edge velocities are studied as a function of film thickness, laser pulsewidth, and incident laser fluence. Edge velocity results are compared to a model of total transmitted fluence incident at the substrate/film interface. A model including laser-induced avalanche ionization and multi-photon ionization mechanisms in the substrate shows a transmitted fluence limit which coincides with observed edge velocity limits.