Excitation regeneration in delay-coupled oscillators

A network of phase-coupled oscillators constitutes a system in which excitable 2π phase slips can be induced by noise. We show that such an excitation in one of the oscillators can be regenerated by subsequent oscillators and become self-sustained for certain topologies. We focus on the simplest such topology: two mutually coupled oscillators. Ours is bolstered by an experimental confirmation of the phenomenon via a pair of mutually delay coupled quantum-dot lasers. Both the intensities and phases of the laser outputs were measured confirming the interpretation.