Non-equilibrium quantum transport theory for quantum cascade lasers

We have developed a fully quantum mechanical and self-consistent non-equilibrium Green's function (NEGF) theory for quantum cascade lasers (QCL). This method takes into account acoustic, polar-optical phonon scattering, impurity, and interface roughness scattering within the self-consistent Born approximation. We present detailed results for the carrier transport and optical gain in a regime where multiple scattering, interference effects, carrier confinement and capture play an equally important role.