Columnar crystal of Yb:LuPO_4 for high-power miniature rod lasers

We report, for the first time to our knowledge, on the laser performance of a sort of miniature columnar Yb:LuPO4 crystal grown from spontaneous nucleation in high-temperature solution. With a very compact resonator longitudinally pumped by a 976-nm diode laser, continuous-wave laser operation is demonstrated with a 2-mm long tiny crystal rod, with output coupling changed over a wide range from 0.5% to 62%, generating a maximum output power of 5.3 W with an optical-to-optical efficiency of 40%, while the slope efficiency being 50%.