Generation of high power (> 7W) yellow-orange radiation by frequency doubling of GaInNAs-based semiconductor disk laser

Abstract

We report recent developments of GaInNAs-based semiconductor disk lasers (SDLs) emitting at around 590 nm. GaInNAs/GaAs (dilute nitride) quantum-wells enable lasing at a wavelength of ∼1180 nm with reduced indium content and hence reduced lattice strain as compared to InGaAs quantum wells [1], leading to SDL operation with output powers of more than 11W using a single gain chip [2]. The importance of dilute nitride material system for generating high power yellow-orange radiation via frequency doubling of ∼1180 nm SDLs has been recently recognized [3]. In the current experiments we use a single gain mirror cavity (shown in Fig. 1) and investigate the conversion efficiency, power stability, and polarization of the frequency converted output beam. The SDL gain mirror had 10 GaInNAs QWs and was grown by molecular beam epitaxy (MBE). The gain chips were capillary-bonded to a wedged diamond heat spreader. An antireflective coating was deposited on top of the heat spreader to alleviate parasitic reflection from the surface of the wedged diamond. The component was attached to a water-cooled copper mount. For frequency doubling, a 4 mm long type-I critically phase-matched beta barium borate (BBO) crystal was placed inside the laser cavity (between folding mirror and the plane mirror).