Highly efficient LD-pumped 607 nm high-power CW Pr3+: YLF lasers

We demonstrated a 607 nm high-power continuous-wave (CW) orange laser based on a 12-mm-long a-cut Pr3+:YLF crystal with high slope efficiency and a low doping level. A maximum output power of 4.88 W with a slope efficiency of similar to 49% was achieved at an absorbed pump power of 12.15 W, and no output saturation power was observed. To improve the laser beam quality, we designed a concave-plane cavity and achieved an output power of 3.80 W with M-2 factors of similar to 1.7 and similar to 2.2 in the horizontal and vertical directions, respectively, by means of a novel output coupler with tunable transmission. In addition, theoretical analyses were conducted to explain our designs, and the corresponding simulated results were presented.