High efficiency diode-pumped Pr:LiLuF4 visible lasers in femtosecond-laser-written waveguides

In this work we investigate the power scaling of diode -pumped Pr:LiLuF4 waveguide lasers produced by direct femtosecond writing. The waveguides studied consisted in depressed cladding waveguides with different geometries. We observed laser emission at 604 nm, achieving a maximum output power of 275 mW and a slope efficiency of 40%, and 721 nm, demonstrating 310 mW of output power and a slope efficiency of 50%. Moreover, we obtained, what we believe is for the first time in a diode -pumped waveguide, laser emission at 523 nm, with a maximum output power of 65 mW and a slope efficiency of 11%. In the end, we also demonstrated the first diode -pumped operation of a single -transverse -mode waveguide laser at 721 nm, reaching a maximum output power of 28 mW and maintaining a high quality beam with an M2 of 1.1. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement