2.55 W continuous-wave 378 nm laser by intracavity frequency doubling of a diode-pumped Alexandrite laser

A high-power continuous-wave (CW) ultraviolet (UV) laser at 378 nm from an intracavity frequency-doubled Alexandrite laser has been demonstrated with 638 nm fiber-coupled laser diodes as the pump source. A maximum output power of 2.55 W was obtained, which is the highest power for CW frequency-doubled Alexandrite lasers, to the best of our knowledge, corresponding to the optical-to-optical conversion efficiency of 7.9% from 638 nm pump laser to 378 nm UV laser. The beam quality factors M-2 were measured to be 2.19 and 2.47 in x and y directions at UV output power of 1 W, respectively. (C) 2021 Optical Society of America

Automated summary

In this study, a high-power continuous-wave ultraviolet laser at 378 nm was successfully demonstrated using an intracavity frequency-doubled Alexandrite laser and 638 nm fiber-coupled laser diodes as the pump source. The maximum output power reached 2.55 W, marking the highest power for CW frequency-doubled Alexandrite lasers to date. The optical-to-optical conversion efficiency from the 638 nm pump laser to 378 nm UV laser was measured to be 7.9%.