GaSb-based VCSELs emitting in the mid-infrared wavelength range (2–3 μm) grown by MBE

We report the growth conditions and operations of electrically pumped monolithic Sb-based type-I quantum-well vertical cavity surface emitting lasers (VCSELs) emitting above 2.2 μm. The structures were grown on (0 0 1)-GaSb substrates by molecular beam epitaxy (MBE) and are made of two N-type GaSb/AlAsSb Bragg reflectors, a GaInAsSb/AlGaAsSb multiquantum-well active region and an InAsSb/GaSb tunnel junction. Growth conditions have been optimized for each target wavelength. Laser emission in CW up to 293 K at 2.3 μm and in pulsed regime at 2.52 μm at room temperature (RT) is demonstrated. These are the longest wavelength achieved with electrically pumped VCSELs to date.