Single-frequency GaInAsSb/AlGaAsSb quantum-well ridge-waveguide lasers emitting at 2.1 μm

Ridge-waveguide lasers emitting at ∼2.1 μm have been fabricated from a GaInAsSb/AlGaAsSb quantum-well heterostructure grown on a GaSb substrate by molecular beam epitaxy. The cw threshold current is as low as 29 mA at room temperature, and the maximum cw output power is 28 mW. The lasers operate in a single longitudinal mode which can be continuously tuned without mode hopping over 1.2 nm by changing the heatsink temperature and over 0.8 nm by changing the current.