Nonequilibrium many-body theory of intersubband lasers

We present a theory for intersubband lasers, based on the solution of the Maxwell-semiconductor Bloch equations for the laser field and active medium. The collision contributions are treated within the relaxation rate approximation, where the relaxation rates are determined by microscopic scattering calculations. The theory is suitable for investigating steady-state as well as dynamical laser characteristics. As examples of applications of the theory, we examine the thermal dependence of the laser output versus current density curve and the response to modulation of the injection current, for a three-subband laser. The influence of the nonparabolicity of the conduction band and Hartree-Fock many-body effects are investigated.