Continuous-wave and Q-switched laser operation of Nd:Gd 0.18Y 0.82VO 4 mixed crystal

Abstract

Efficient continuous-wave (cw), passively Q-switched, and actively Q-switched laser operations are demonstrated with a mixed vanadate crystal of Nd:Gd 0.18Y 0.82VO 4 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 Cr 4+: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 μJ, 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 μJ, 10.5 ns, and 17.5 kW, respectively.