LD-pumped Passively Q-Switched Nd:GdVO4 Laser at 1342 nm with High Initial Transmission V:YAG Saturable Absorber

We have realized, for the first time to our knowledge, the passive Q-switching operation of an LD-pumped Nd:GdVO4 laser at 1342 nm with V:YAG saturable absorber of initial transmission as high as 96%. This laser is investigated under different transmissions of the output coupler. The dependences of average output power, pulse width, pulse repetition rate, single-pulse energy and peak power on incident pump power are also measured. The shortest pulse width of 80 ns, the maximum single-pulse energy of 19.5 mu J and the highest peak power of 244 W are obtained with the output coupler of T = 15% and the pump power of 7.93 W. We find a special experimental phenomenon that the pulse repetition rate begins to drop after reaching the peak with the increase of the pump power. This phenomenon is analyzed and the theoretical calculations are consistent with the experimental results.