Passively Q-switched, intracavity frequency-doubled YVO4/Nd:YVO4/KTP green laser with a GaAs saturable absorber

A diode-pumped, passively Q-switched, intracavity frequency-doubled YVO₄/Nd:YVO₄/KTP green laser is realised using a GaAs saturable absorber. Two pieces of GaAs wafers are employed in the experiment. In using a 400-μm-thick GaAs wafer and an incident pump power of 10.5 W, the maximum output power of the passively Q-switched green laser is 362 mW at a pulse repetition rate of 84 kHz and a pulse duration of 2.5 ns. When use is made of a 700-mm-thick GaAs wafer, the minimum pulse duration is 1.5 ns at a repetition rate of 67 kHz, pulse energy of 4.18 μJ and peak power of 2.8 kW.