Laser-diode pumped Nd: GdVO4 ultraviolet laser with LBO frequency tripling

We have demonstrated a laser-diode pumped Nd: GdVO₄ extra-cavity frequency tripling ultraviolet laser with a LBO crystal in this paper. Under the acousto-optic (A-O) Q-switched operation, we have obtained 355 nm ultraviolet laser, with pulse width of 25 ns and pulse repetition rate of 20 kHz. By using a type I non-critical phase-matched LBO crystal, the SHG output power of 822 mW is achieved at the incident pump power of 16 W. The output power of 355nm UV laser is 260mW with a type II phase-matched LBO crystal, and the conversion efficiency (1 064 nm-355 nm) is 5.9 %. The power stability of 355 nm laser is 1.7% in 1 h. Supported by Natural Science Foundation of Shandong under No. Z003A01.