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 p icosecond laser pulses is reported. Ablated plume edge velocities are studi ed as a function of film thickness, laser pulse width, and incident laser f luence. Edge velocity results are compared to a model of total transmitted fluence incident at the substrate/film interface. A model including laser-i nduced avalanche ionization and multiphoton ionization mechanisms in the su bstrate shows a transmitted fluence limit which is consistent with observed edge velocity limits. (C) 1999 American Institute of Physics. [S0021-8979( 98)01824- 6].