Passive Q switching of Nd:YAG lasers by use of bulk semiconductors

Abstract
We report passive Q switching of Nd:YAG lasers with the use of a bulk InGaAsP film, grown on an InP substrate by liquid-phase epitaxy, as an intracavity saturable absorber. The single Q-switched pulse had a maximum energy of 1.65 mJ with a 20-ns duration. The simple technology is easily extendible to any infrared solid-state laser.