Q-SWITCHING OF A DIODE-PUMPED ND-YAG LASER WITH GAAS

We investigated the properties of a diode-pumped Nd:YAG laser that is passively Q switched by a thin, single-crystal GaAs wafer. At 3 W of i ncident pump power, the laser produced stable 7-ns pulses with 20 mu J of energy at a 6-kHz repetition rate. For pump powers up to 2.2 W, wh ich resulted in 13.2-mu J pulses, the output mode was TEM(00). The sho rtest pulses that we observed were 3 ns in duration. In addition to sa turable absorption, we find that two-photon absorption and free-carrie r effects determine pulse formation. (C) 1996 Optical Society of Ameri ca