Pseudo-spatial coherence resonance in an excitable laser with long delayed feedback.

ABSTRACT

The effect of noise in an excitable semiconductor laser with feedback is studied in the framework of the spatio-temporal representation of long delayed systems. Propagation, noise-induced creation, and destruction of excitable pulses in the pseudo time are observed. The addition of a variable quantity of noise leads to the occurrence of a phenomenon that we term "pseudo-spatial coherence resonance." A phenomenological model well describes the system and allows for a comparison with the experimental observations. A simple Monte Carlo approach is also introduced and permits to explain the features observed in terms of the key dynamical ingredients of the physical system.