LD pumped all-solid-state continuous-wave ultraviolet laser

A laser-diode (LD) pumped Nd:YVO4 intracavity frequency tripling all-solid-state Continuous-wave (CW) ultraviolet laser at 355 nm was reported. In cavity, the type Ⅱ phase-matched KTP crystal was used for Second Harmonic Generation (SHG) of the fundamental 1064 nm radiation to generate 532 nm radiation, and the type Ⅰ phase-matched LBO crystal was used as a Sum Frequency (SM) of the 1064 nm radiation and the 532 nm radiation to generate 355 nm radiation. The flat outside section of the Nd:YVO4 crystal HR coated for both 1064 nm and 532 nm radiations was used as the input mirror. The output mirror was concave. Therefore, plano-concave cavity was composed of these two mirrors. Even at moderate pump power, the Nd:YVO4 crystal will produce thermal lens. In considering the effect of thermal lens, the cavity was designed finely. At the pump power of 3W, the CW 355 nm radiation of 4.2 mW was obtained.