Statistics of power-dropout events in semiconductor lasers with time-delayed optical feedback

We measure experimentally the statistical distribution of time intervals between power-dropout events occurring in a semiconductor laser with time-delayed optical feedback operating in the low-frequency fluctuation regime. Near the laser threshold, the time-interval probability distribution displays a low-probability region, or dead zone, for short times, followed by a slow rise, and an exponential decay for long times. At higher injection currents, the distributions develop considerable structure. We compare our results to the predictions of approximate analytic models of the laser dynamics and find that no single model accurately captures the details of the observed distributions, indicating that our physical understanding of the long-term dynamics of the laser in this regime is less than complete. [S1050-2947(97)50711-6].