Well-barrier hole burning in quantum well lasers

The reported wide variations in the damping behavior of quantum well lasers are explained by a novel theory of nonlinear gain, well-barrier hole burning. In the model a spatial hole develops perpendicular to the active region involving carriers moving between the wells and the barrier/confinement layers. The modified rate equations describing well-barrier hole burning are presented. An analytical approximation for the nonlinear gain coefficient epsilon , valid only under certain conditions, is given. A numerical solution is given for the case of high photon densities and large capture-times. It is shown how well-barrier hole burning explains the measurements of the increased spontaneous emission from the barrier/confinement region above threshold. Various higher-than-expected damping rates reported in some quantum well lasers are shown to be consistent with the model.<>