Room Temperature CW Operation of GaSb/AlGaSb MQW Laser Diodes Grown by MBE

CW operation was achieved by a mesa-stripe (10 µm wide and 200 µm long) GaSb(12 nm)/Al 0.35 Ga 0.65 Sb(3 nm) modified multi-quantum-well (MQW, 6 wells) laser diode grown by molecular beam epitaxy (MBE) with threshold current I th =145 mA at 14°C. Lasing wavelength was 1.662 µm at 9°C. Keys to this achievement were optimizations in (i) MBE growth condition, (ii) layer structure of the MQW wafer (introduction of a superlattice buffer layer and high barrier layers in MQW), and (iii) device fabrication processes. This is the first realization of room temperature cw operation among any type of laser diodes made from an Al-Ga-Sb material system.