Multi-stable regime and intermediate solutions in a nonlinear saturable coupler

TL;DR

This paper demonstrates the existence of multi-stable regimes and intermediate solutions in a nonlinear saturable coupler through theoretical predictions and experimental validation, revealing fundamental properties relevant to extended nonlinear systems.

Contribution

It provides the first experimental evidence of unstable symmetry-broken solutions in a saturable coupler and links basic unit behavior to extended lattice properties.

Findings

Identification of multi-stable propagation regimes

Experimental confirmation of intermediate solutions

First observation of unstable symmetry-broken solutions

Abstract

We show, theoretically and experimentally, the existence of a multi-stable regime in a nonlinear saturable coupler. In spite of its simplicity, we found that this model shows generic and fundamental properties of extended saturable lattices. The study of this basic unit becomes crucial to understand localization mechanisms and dynamical properties of extended discrete nonlinear saturable systems. We theoretically predict the regions of existence of intermediate solutions, and experimentally confirm it by observing a multi-stable propagation regime in a LiNbO3 saturable coupler. This constitutes the first experimental evidence of the existence of these unstable symmetry-broken stationary solutions.