Towards Power Scaling of Simple CW Ultraviolet via Pr: LiYF<sub>4</sub>-LBO Laser at 320 nm
Teng Zhang, Wanxin Zheng, Kai Feng, Dong Wang, Bin Xu, Zhengqian Luo, Zhenfang Yu, Xudong Cui, Mauro Luciano Baesso, T. Catunda
Abstract
Intracavity frequency doubling of diode-pumped continuous-wave Pr<sup>3+</sup> laser in visible spectral region is a highly efficent and cost-effective method for the generation of high-performance continuous-wave ultraviolet laser. However, to date, diode-pumped continuous-wave frequency doubled Pr<sup>3+</sup>-based ultraviolet laser has still been power limited only to about one watt. In this work, employing two 12-W blue diode lasers as pump sources individually, we achieved maximum output powers up to 1.82 W and 1.73 W of ultraviolet lasers at about 320 nm by intracavity frequency doubling of continuous-wave Pr:LiYF<sub>4</sub> (YLF) lasers at 640 nm. The used nonlinear frequency doubler is a 12-mm LBO crystal. For further power scaling of the ultraviolet laser, a total pump power of 24 W was injected into the laser crystal by configuring a double end pumping geometry. Under this situation, a maximum output power of 3.22 W can be achieved, which is believed to be the highest continuous-wave ultraviolet laser via intracavity frequency doubling. This solid-state 320-nm ultraviolet laser could replace the relatively cumbersome He-Cd vapor laser for a variety of applications.