  A midinfrared quantum cascade laser with high wall-plug efficiency is
analyzed by means of an ensemble Monte Carlo method. Both the carrier transport
and the cavity field dynamics are included in the simulation, offering a
self-consistent approach for analyzing and optimizing the laser operation. It
is shown that at low temperatures, photon emission and absorption can govern
the carrier transport in such devices. Furthermore, we find that photon-induced
scattering can strongly affect the kinetic electron distributions within the
subbands. Our results are validated against available experimental data.
