Influence factors on pulsewidth reduction of high power AO Q-switching DPSL

Using Q-Switching rate equation, from the viewpoint of internal relations between the gain of active medium and the loss of resonator, the influence the multiparameters of resonator on pulsewidth are explicated. The theoretical prediction is validated through experiments. In the experiment, high efficient optical coupling and pumping cavity are adopted. AO Q-switched diode-side-pumped Nd:YAG laser is developed. The laser is pumped by 35 × 20 W CW diode arrays. The size of active medium is Φ 4 mm × 115 mm. By using fused quartz crystal for AO Q-switching, at pumping current I=22.2 A. A Q-Switching pulse of 45.8ns FWHM and 246kW peak power at 1064 nm with 10 kHz repetition rate are acquired. The optical-to-optical conversion efficiency and the electrical-to-optical conversion efficiency are 21.3% and 8.5% respectively.