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Metalorganic chemical vapor deposition of GaAs-based laser diodes, using self-organized InGaAs quantum dots ͑QDs͒, emitting at Ͼ1.24 m is demonstrated. The environment-friendly alternative precursor tertiarybutylarsine is used as a substitute for arsenic hydride. The active region contains ten closely stacked InGaAs QD layers embedded in a GaAs matrix. Lasing emission at such long wavelengths was achieved by overgrowing the In 0.65 Ga 0.35 As QDs with a thin In 0.2 Ga 0.8 As film. The application of an in situ annealing step leading to the evaporation of plastically relaxed defect clusters is shown to be decisive for the laser performance. A transparency current density of 7.2 A/cm 2 per QD layer and an internal quantum efficiency of 75% were achieved at room temperature.

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High-brightness edge-emitting semiconductor lasers having a vertically extended waveguide structure emitting in the 1060 nm range are investigated. Ridge waveguide (RW) lasers with 9 μm stripe width and 2.64 mm cavity length yield highest to date single transverse mode output power for RW lasers in the 1060 nm range. The lasers provide 1.9 W single transverse mode optical power under continuous-wave (cw) operation with narrow beam divergences of 9° in lateral and 14° (full width at half maximum) in vertical direction. The beam quality factor M2 is less than 1.9 up to 1.9 W optical power. A maximum brightness of 72 MWcm−2sr−1 is obtained. 100 μm wide and 3 mm long unpassivated broad area lasers provide more than 9 W optical power in cw operation.