title: Laser-induced damage and ion emission of GaAs at 1.06 microm.
abstract: This study focused on the multipulse laser damage and the subdamage threshold ion emission of GaAs. The initial goals were to determine the pulse-dependent damage threshold and to correlate ion emission with surface damage. A Q-switched Nd:YAG laser was used to irradiate the (100) GaAs samples. Using values of N from 1 to 100, we obtained accumulation curves based on 50% damage probability. Corresponding damage threshold fluences were 0.4-0.8 J/cm2 for N > 1 and 1.5 J/cm2 for N = 1. We observed large site-to-site fluctuations in ion emission and found the onset of emission at 0.2 J/cm2 for all cases. Once surface damage occurred, ion emission increased greatly. The observed behavior supports a surface cleaning model for the ion emission which precedes surface damage. Measurements of linear and nonlinear free carrier absorption were made, but no anomalous absorption was observed.
authors.affiliation: University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Huang
authors.forename: M F
authors.initials: MF
authors.lastname: Becker
authors.forename: R M
authors.initials: RM
authors.lastname: Walser