Theory of multimode effects including noise in semiconductor lasers

In recent years a number of powerful methods have been developed that treat quantum fluctuations in ordinary lasers. Among these are quantum mechanical Langevin equations and a -number Fokker-Planck equation associated with quantum systems. First, the quantum mechanical Langevin equations for the semiconductor laser are shown. Then the extension of the Fokker-Planck method to multimode action in semiconductor lasers is given, and then the exact stationary solution, which predicts the relative probability of mode configurations. In particular the Paoli-Ripper model that treats in a combined way the intrinsic resonance of a single-mode semiconductor laser and the effect of nonlinear polarization is discussed.