Modeling mode competition in laser diodes

We present an advanced model for the simulation of laser dynamics based on the microscopic many-particle equations of motion and going beyond the often used rate equation model. Our model is used to simulate (Al,In)GaN based edge-emitting laser diodes showing longitudinal mode-competition phenomena which are responsible for the effect of mode hopping, i.e. the modes are switched on and off causing mode rolling from higher to lower frequencies. We show that the effect is caused by beating vibrations of the carrier density which result in an asymmetric coupling term between neighboring modes. Here, the results agree with the case where we assume that the coupling of two modes is independent of all the other modes, as long as the mode frequencies are not equidistant. If the mode frequencies are equidistant, the mode dynamics depend strongly on the initial phases and the initial noise.