Room-temperature, monolithic, electrically-pumped type-L quantum-well Sb-based VCSELs emitting at 2.3 µm

An all-epitaxial monolithic vertical cavity surface emitting laser grown on GaSb substrate is presented. The structure is composed of two n-doped AlAsSb/GaSb distributed Bragg reflectors, a type-I GaInAsSb/AlGaAsSb multi-quantum-well active region and a tunnel junction. Quasi continuous-wave laser operation is demonstrated at 2.3 µm up to room temperature. Threshold current densities of 0.8 and 0.6 kA/cm2 are obtained at 300 and 280 K for 80 µm-diameter devices (1 µs pulses, 10% duty cycle). A peak output optical power of 2 mW was achieved at 280 K.