Observation of chaotic itinerancy in the light and carrier dynamics of a semiconductor laser with optical feedback

We report a direct experimental observation of chaotic itinerancy in simultaneous measurements of the light intensity and voltage fluctuations of a laser diode exhibiting low-frequency fluctuations. The distribution of trajectories leading up to (following) an intensity dropout is computed from the experiment and reveals the presence of itinerant mechanisms before (after) dropout initiation. A phase space reconstruction of the trajectory for the optimal path of motion illustrates sudden shifts between low-dimensional attractor ruins and is shown to correspond to simulations of the laser intensity and carrier number.