679/339.5 nm radiation generation of pr: YLF laser pumped by fiber coupled blue laser diode module

We demonstrate the high-power continuous-wave (CW) operation of a Pr: YLF laser at 679 nm by suppressing the higher gain transitions near 640 nm, 670 nm and 698 nm. For 679 nm, the maximum output power is 3.5 W. The absorbed pumping power is 22 W in sigma polarization. The optical-to-optical conversion efficiency is quite high, reaching 15.9%, and the output power stability in 2 h is better than 0.5%. Moreover, intracavity second harmonic generation had been achieved output power of 620 mW at 339.5 nm by using a LBO nonlinear crystal. To the best of our knowledge, laser diode-pumped laser action at 679/339.5 nm was demonstrated for what is believed to be the first time.