Continuous-wave efficient cyan-blue Pr:YAlO _3 laser pumped by InGaN laser diode

We report on the first continuous-wave quasi three-level laser emitting in the cyan-blue spectral range in praseodymium-doped oxide materials, as we believe. Pr:YAlO _3 crystal, cooled to the cryogenic temperatures, was used as an active medium. To minimize resonator losses, the cavity mirrors were directly deposited on the crystal faces to form a microchip geometry. More than half-Watt of the output power at 493 nm wavelength with a slope efficiency of 26