Bubbling in delay-coupled lasers

TL;DR

This paper investigates chaos synchronization in delay-coupled lasers, revealing how different relay types affect stability and how bubbling phenomena can be suppressed using active relays.

Contribution

It provides a theoretical analysis of chaos synchronization in delay-coupled lasers, highlighting the effects of relay type and methods to suppress bubbling phenomena.

Findings

Bubbling causes noise-induced desynchronization in laser systems.

Passive relays can lead to bubbling, while active relays can suppress it.

Desynchronization is linked to transverse instability of antimodes.

Abstract

We theoretically study chaos synchronization of two lasers which are delay-coupled via an active or a passive relay. While the lasers are synchronized, their dynamics is identical to a single laser with delayed feedback for a passive relay and identical to two delay-coupled lasers for an active relay. Depending on the coupling parameters the system exhibits bubbling, i.e., noise-induced desynchronization, or on-off intermittency. We associate the desynchronization dynamics in the coherence collapse and low frequency fluctuation regimes with the transverse instability of some of the compound cavity's antimodes. Finally, we demonstrate how, by using an active relay, bubbling can be suppressed.