GaAs/AlGaAs superlattice quantum cascade lasers at lambda approximate to 13 mu m

We report the realization of an injection laser based on intraband transiti ons in a finite AlGaAs/GaAs superlattice. The active material is a 30 perio d sequence of injectors/active regions made from AlGaAs/GaAs quantum wells. By an applied electric field, electrons are injected into the second minib and of a chirped superlattice and relax radiative to the lowest miniband. A t a heat-sink temperature of 10 K, the laser emission wavelength is 12.9 mu m with peak optical powers exceeding 100 mW and a threshold current densit y of 9.8 kA/cm(2). The maximum operating temperature is 50 K. For this devi ce, a waveguide consisting of heavily doped GaAs cladding and low doped cor e layers has been used as a plasma-enhanced confinement. (C) 1999 American Institute of Physics. [S0003-6951(99)01236-X].