GaSb-based mid-infrared quantum well diode lasers

The current status of GaInAsSb/AlGaAsSb quantum-well (QW) lasers emitting at approximately 2 micrometers and InAsSb/InAlAsSb QW lasers emitting at approximately 4 micrometers is described. At room temperature, GaInAsSb/AlGaAsSb lasers have exhibited pulsed threshold current density as low as 143 A/cm² and cw power of 1.3 W from a 300- micrometers aperture. Ridge-waveguide lasers have operated cw up to 130 degree(s)C, with a maximum power of 100 mW in a single lobe at 20 degree(s)C. From a tapered laser, diffraction-limited cw power of 200 mW has been obtained. The InAsSb/InAlAsSb QW broad- stripe lasers have operated pulsed up to 165 K, with a characteristic temperature of 30 K up to 120 K. At 80 K, cw power up to 30 mW/facet has been obtained. Ridge-waveguide lasers have exhibited cw threshold current of 35 mA at 80 K, and operated cw up to 128 K.