Spatial decorrelation in broad-area edge-emitting semiconductor amplifiers

We analyze experimentally the spatio-temporal dynamics of the transverse structures appearing in broad area edge-emitting semiconductor amplifiers under CW optical injection. We demonstrate that, in certain conditions, the light reflected by the system exhibits a multipeaked structure whose dependence on the parameters suggests an interpretation in terms of cavity solitons. These structures can exhibit self-pulsations with periods of the order of few milliseconds, which we explain in terms of regenerative thermal oscillations. In a particular device, we generate two single-peak structures which are spatially uncorrelated, as required for cavity solitons. A microscopic model shows good agreement with the main body of the experimental results.