Excitability in optical systems close to Z2-symmetry

TL;DR

This paper investigates excitability in semiconductor ring lasers near Z2-symmetry, combining theoretical analysis and experiments to understand and control the phenomenon by symmetry breaking.

Contribution

It introduces a mechanism of excitability near Z2-symmetry and demonstrates how to experimentally induce and verify it in semiconductor ring lasers.

Findings

Theoretical prediction of excitability mechanism near Z2-symmetry.

Experimental confirmation of excitability in semiconductor ring lasers.

Controlled symmetry breaking induces excitability as predicted.

Abstract

We report theoretically and experimentally on excitability in semiconductor ring lasers in order to reveal a mechanism of excitability, general for systems close to Z2-symmetry. The global shapes of the invariant manifolds of a saddle in the vicinity of a homoclinic loop determine the origin of excitability and the fea- tures of the excitable pulses. We show how to experimentally make a semiconductor ring laser excitable by breaking the Z2-symmetry in a controlled way. The experiments confirm the theoretical predictions.