GaInAs/AlGaAsSb quantum-cascade lasers

Quaternary-barrier-containing GaInAs/A1GaAsSb quantum-cascade lasers, motivated by reducing the barrier height compared to that in GaInAs/A1AsSb quantum-cascade lasers, have been demonstrated. The design of these quaternary-barrier-containing lasers is based on triple-quantum-well vertical-transition active regions, and their fabrication relies on molecular-beam-epitaxial growth of Ga(0.47)In(0.53)As/AlGaAs(1-x)Sb(x) (x close to 0.45) heterostructures on n-InP substrates. Including twenty-five periods of active regions and injection regions, the quantum-cascade lasers operate up to T >= 400 K in pulsed mode, with an emission wavelength of about 4.9 µm at room temperature. The characteristic temperature T(0) of the threshold current density is 169 K in the temperature range between 280 and 400 K.