GaInAs/AlAsSb quantum-cascade lasers operating up to 400 K

Above room-temperature (T>=400 K) operation of GaInAs/AlAsSb-based quantum-cascade lasers has been demonstrated. The lasers are based on vertical-transition active regions and consist of 25 periods of Ga(0.47)In(0.53)As/A1As(0.56)Sb(0.44) active/injection regions grown lattice-matched on InP substrates by molecular-beam epitaxy. They emit at a wavelength of Lambda about 4.5 mu m. For a device with the size of 18 mu m X 2.8 mm mounted substrate-side down with as-cleaved facets, a maximum peak power per facet of 750 mW has been achieved at 300 K and remains as high as 30 mW at 400 K. The characteristic temperature T(0) of the threshold current density is 171 K in the temperature range between 280 K and 400 K