Diode-pumped Pr^3+:KY_3F_10 red laser

We report the first observation to our knowledge of room-temperature continuous-wave laser operation of a Pr(3+):KY(3)F(10) single crystal at 644.5 nm, pumped by a blue GaN laser diode emitting at 446 nm. With a 2.5% transmission output coupler and a nonoptimized optical cavity, an output power of 39 mW was obtained at 644.5 nm with a laser threshold of 125 mW and a differential slope efficiency of 23%.