Continuous-Wave Ultraviolet Generation at 349 nm by Intracavity Frequency Doubling of a Diode-Pumped $\hbox{Pr:LiYF}_{4}$ Laser

We report a continuous-wave ultraviolet laser at 349 nm obtained by intracavity frequency doubling of a diode-pumped Pr 3+ -doped LiYF 4 laser. Power scaling of lasers at 698-nm fundamental wavelength was realized using an InGaN laser diode with a maximum output power of 850 mW and a 5-mm-long 0.5 a.t. % laser crystal. The maximum output power at 698 nm was 215 mW. With beta barium borate crystal employed as the nonlinear medium, 33 mW of output power at 349 nm has been achieved.