GaInSb/AlGaAsSb strained quantum well semiconductor lasers for 1.55 μm operation

Gallium antimonide and related compounds are promising materials for fabricating monolithic vertical cavity semiconductor lasers operating at telecommunications wavelengths. With that aim active layers based on Ga0.96In0.04Sb/Al0.5Ga0.5As0.04Sb0.96 multiquantum wells have been evaluated by means of a separate-confinement laser diode structure grown on a GaSb substrate by molecular beam epitaxy. Owing to optimization of the growing process, for the well/barrier structure, laser emission at 1.4 mu m has been obtained at 80 K with a threshold current as low as 15 mA for a 640 mu m long and 15 mu m wide mesa stripe structure. At room temperature laser emission occurred at 1.55 mu m with a pulsed threshold current density of 4 kA cm(-2) according to the measured characteristic temperature of 50 K. In a first attempt such an active layer has been included in a 1.5 mu m microcavity involving antimonide Bragg mirrors.