Self-focusing of near-infrared laser beams in GaAs

Abstract

Self‐focusing of Q‐switched Nd‐YAG laser radiation in single‐crystal GaAs has been studied. Near‐ and far‐field intensity distributions measured after the light has passed through 1 cm of GaAs are given for various incident pulse energies. The self‐focusing correlates qualitatively with linear absorption but is found to be most pronounced in p‐type material. This self‐focusing is believed to be of thermal origin, resulting from absorption coupled with a refractive index that increases with temperature.