In As ∕ Al As Sb based quantum cascade lasers

The advantages and drawbacks of the different semiconductor materials which can be used for the fabrication of quantum cascade laser (QCL) emitting in the 3–4μm wavelength range bring us to propose a material combination which can be lattice matched to InAs substrate. It is shown that using InAs quantum wells and AlAsSb barriers, it is possible to balance the strain in QCL structures made on InAs whatever the active region design and the wavelength targeted. A first InAs∕AlAsSb QCL structure has been grown and fully characterized by x-ray diffraction. The devices emit at 3.5μm at 300K in pulsed mode.