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

Abstract

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 pulse width, 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 multiphoton ionization mechanisms in the substrate shows a transmitted fluence limit which is consistent with observed edge velocity limits.