Doping in quantum cascade lasers.: II.: GaAs/Al0.15Ga0.85As terahertz devices

The performances of GaAs/Al0.15Ga0.85As terahertz quantum cascade lasers based on a bound-to-continuum transition are investigated as a function of injector doping. A linear dependence between threshold current and doping is found and agrees with the expected increase of waveguide losses due to free carrier absorption. (c) 2006 American Institute of Physics.