Q-switching of diode-end-pumped Nd:YVO4 laser with GaAs output coupler

To improve the compactness of Q-switched diode-pumped solid-state lasers, a passively Q-switched diode-end-pumped Nd:YVO4 laser was constructed using undoped and uncoated GaAs wafers as saturable absorbers as well as output couplers. GaAs wafers with two different thicknesses, 625 mu m and 500 mu m, were employed and their corresponding experimental results were compared. The results were also compared with those obtained with an active A-O Q-switch with similar cavity configuration and pumping condition. It is found that the Fabry-Perot effect of the GaAs wafer played an important role in shortening the Q-switched pulses and stabilizing the laser operation. The performance of passive Q-switching using the GaAs wafer with Fabry-Perot effect was better than that of both the passive GaAs Q-switching without Fabry-Perot effect and the active A-O Q-switching.