LD Pumped Nd:GdVO_4 Crystal Ultraviolet Laser with LBO Frequency Tripling

A laser-diode(LD) pumped Nd:GdVO_4 extra-cavity frequency tripling ultraviolet laser with a LBO crystal was demonstrated.Under the acousto-optic(A-O) Q-switched operation,we obtain 355 nm ultraviolet laser,with pulse width of 25 ns and pulse repetition rate of 20 kHz.Using a type Ⅰ phase-matched LBO crystal,the output power of second-harmonic generation(SHG) reaches to 822 mW at incident pump power of 16 W.The output power of 355 nm ultraviolet laser is 260 mW with a type Ⅱ phase-matched LBO crystal,and the conversion efficiency (1 064～355 nm) is 5.9%.The stability of power at 355 nm is 1.7% in an hour.