Continuous-wave ultraviolet generation at 320 nm by intracavity frequency doubling of red-emitting praseodymium lasers

We describe a new approach for the generation of coherent ultraviolet radiation. Continuous-wave ultraviolet light at 320 nm has been obtained by intracavity frequency doubling of red-emitting Praseodymium lasers. Lasing at the 640-nm fundamental wavelength in Pr:LiYF4 and Pr:BaY2F8 was realized by employing an optically pumped semiconductor laser at 480 nm as pump source. Using LiB3O5 as nonlinear medium, similar to 19 mW of ultraviolet radiation with similar to 9% optical efficiency with respect to absorbed power was reached for both laser crystals; the visible-to-ultraviolet conversion efficiency was 26% and 35% for Pr:LiYF4 and Pr:BaY2F8, respectively. (c) 2006 Optical Society of America.