An Efficient Diode-Pumped Acousto-Optically Q-Switched Ho :YVO4 Laser

We demonstrate the continuous-wave and acousto-optically Q-switching performance of Ho :YVO4 laser with the diode-pumping structure. A fiber-coupled laser diode at 1.91 mu m is employed as the pump source. In the continuous-wave operation, a maximum output power of 4.11 W at 2053.2 nm is achieved at an absorbed pump power of 20.4 W, corresponding to a slope efficiency of 37.6% with respect to the absorbed pump power. In the Q-switching regime, a maximum pulse energy of 1.49 mJ at absorbed pump power of 20.4 W is obtained with a pulse repetition frequency of 2 kHz. We achieve simultaneously the minimum pulse width equal to 11.9 ns and the peak power equal to 125.5 kW.