Continuous-wave and Q-switched laser operation of Nd:Gd0.18Y0.82VO4 mixed crystal

Efficient continuous-wave (cw), passively Q-switched, and actively Q-switched laser operations are demonstrated with a mixed vanadate crystal of Nd:Gd0.18Y0.82VO4 under diode pumping. In a cw operation, an output power of 8.25 W is obtained at a maximum available incident pump power (P-in) of 15 W, With a slope efficiency of 56%. Using a Cr4+:YAG crystal of initial transmission of 62% as the saturable absorber for Q-switching, an average output power of 3.05 W is generated at pulse repetition frequency (PRF) of 16.7 kHz when the laser is pumped with the same maximum P-in. The pulse energy, pulse duration, and peak power are 183.3 mu J, 6.0 ns, and 30.6 kW, respectively. When actively Q-switched by an acousto-optic modulator, the laser produces an average output power of 5.5 W at PRF of 30 kHz with 16.2 W of pump power incident upon the laser crystal. The pulse energy, duration, and peak power are measured to be 183 mu J, 10.5 ns, and 17.5 kW, respectively. (C) 2010 Elsevier Ltd. All rights reserved.