Intra-cavity frequency-doubling of a Nd:YAG laser passively Q-switched with GaAs

Abstract

A simple and compact all-solid-state green-pulse laser source is described. A diode-pumped Nd:YAG laser is Q-switched by a GaAs saturable absorber and intra-cavity frequency-doubled by a KTP crystal. At 3.7 W of pump power the device produces high-quality 20.5-μJ, 25-ns pulses at a pulse repetition rate of 12 kHz. The dynamics of the pulse formation is described by rate equations and an energy-level model which accounts for the various energy-transfer processes in GaAs.