Spatio-Temporal Dynamics in Semiconductor Lasers with Delayed Optical Feedback

We investigate the influence of delayed optical feedback (DOF) on the dynamics of semiconductor lasers. In the case of the narrow single-stripe laser, we find that the presence of DOF leads to a wealth of dynamical phenomena in the coherence-collapsed regime, including mode-hopping between compound-cavity modes induced by DOF. Focusing on the twin-stripe laser — the most simple system with inherent spatio-temporal instabilities — we show that feedback may both induce and suppress spatio-temporal instabilities. Eigenmode analysis enables us to determine and identify the underlying spatio-temporal "supermodes". For appropriately chosen parameters, regular regimes including continuous wave operation can be obtained from an originally chaotic regime. For moderate to strong feedback, interaction between the spatial degrees of freedom in the twin-stripe laser and the compound cavity modes leads to a new phenomenon which we term "spatio-temporal mode-hopping".