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.
© 1986 Optical Society of America
Austin L. Huang, Michael F. Becker, and Rodger M. Walser, "Laser-induced damage and ion emission of GaAs at 1.06 µm," Appl. Opt. 25, 3864-3870 (1986)