Nonlinear dynamics of semiconductor laser arrays

The simulated output is shown of a 2-stripe index guided array and a 4-stripe gain guided array under constant pump conditions. The results of the partial differential equation (PDE) model for the strongly-index-guided array confirm the predictions of coupled-mode theory. The pulsations observed in laser arrays have several origins. One is the breakdown of phase locking due to amplitude-phase coupling. Another is the beating between multiple lateral modes which can drive the relaxation oscillations. A third mechanism is related to saturable absorption in the unpumped inter-element regions. We elucidate these mechanisms and present experimental results for index guided, antiguided, and gain guided arrays.