High-efficiency direct-pumped Nd: YVO4 laser operating at 1.34 μm

We report a high-efficiency Nd: YVO4 laser operating at 1342 nm pumped by an all-solid-state Q-switched Ti: Sapphire laser at 879 nm. A plano-concave cavity was optimized to obtain high efficiency and good beam quality. Output power for two Nd: YVO4 crystals with 1.0- and 3.0-at.% Nd3+ doping under 879-nm pumping was measured respectively. Comparative results obtained by traditional pumping at 808 nm into the highly absorbing F-4(5/2) level were presented, showing that the slope efficiency of the 1.0- at.% Nd: YVO4 laser under 879- nm pumping was 10.5% higher than that of 808-nm pumping. In a 4-mm-thick, 1.0- at.% Nd: YVO4 crystal, a high slope efficiency of 64% was achieved under 879-nm pumping, with an optical-to-optical conversion efficiency of 41.3%. (C) 2008 Optical Society of America.