Green, orange, and red Pr3+:YLiF4 epitaxial waveguide lasers

Efficient guided laser oscillation in the visible spectral region is demonstrated with praseodymium-doped YLiF4 layers grown by liquid phase epitaxy. By exciting Pr3+ ions at 479.2 nm with an optically pumped semiconductor laser, maximum slope efficiencies of 40% at 639 nm and 32% at 604 nm are obtained in a cw regime. Green laser oscillation at 522.5 nm, in a quasi-cw regime, with an average output power of 66 mW, is demonstrated for the first time, to our knowledge, in a crystalline fluoride epitaxial waveguide. Furthermore, a record efficiency of 60% at 639 nm in the quasi-cw regime is reported. (C) 2014 Optical Society of America