Locking-unlocking dynamics of mutually coupled laser diodes for extreme events (Invited Paper)

Mutually coupled single-mode laser diodes are investigated to yield extreme events. While the two lasers are found to be mutually locked into continuous-wave emissions of constant intensities, occasional interruptions by unlocking yield strong pulses in an intermittent manner. The high relative occurrences approaching 1% are attained for generating strong microwave pulses with intermittent timing. On one hand, the extreme events are investigated via the equivalent space-time maps in observing their emergences, thereby disclosing the physical mechanisms for their stochastic formation across consecutive round trips through the antiguidance effect of the injected lasers. On the other hand, the timing information related to their occurrences is analyzed with particular attention on identifying a Poisson process instead of a log-Poisson process. The resultant generation of microwave pulsations with widths of the order of 100 ps and amplitudes exceeding 6 times the standard deviation are potentially applicable to wireless propagation in the Ku band.