Amplitude-phase coupling drives chimera states in globally coupled laser networks

TL;DR

This paper demonstrates the existence of stable chimera states in a small, globally coupled laser network, driven by amplitude-phase coupling and multistability, challenging previous assumptions about chimera state conditions.

Contribution

It reveals that amplitude-phase coupling enables chimera states in small, globally coupled laser networks, even with random initial conditions, contrary to prior requirements.

Findings

Chimera states exist in a four-laser globally coupled network.

Amplitude-phase coupling is essential for chimera formation.

Chimera states are stable despite random initial conditions.

Abstract

For a globally coupled network of semiconductor lasers with delayed optical feedback, we demonstrate the existence of chimera states. The domains of coherence and incoherence that are typical for chimera states are found to exist for the amplitude, phase, and inversion of the coupled lasers. These chimera states defy several of the previously established existence criteria. While chimera states in phase oscillators generally demand nonlocal coupling, large system sizes, and specially prepared initial conditions, we find chimera states that are stable for global coupling in a network of only four coupled lasers for random initial conditions. The existence is linked to a regime of multistability between the synchronous steady state and asynchronous periodic solutions. We show that amplitude-phase coupling, a concept common in different fields, is necessary for the formation of the chimera states.