Topological Phenomena in Classical Optical Networks

TL;DR

This paper presents a scheme for realizing topological insulators in classical optical networks using passive elements, analyzing the effects of Kerr nonlinearities on their topological properties and edge modes.

Contribution

It introduces a novel optical network design for topological insulators and extends analysis to nonlinear regimes with Kerr effects.

Findings

Broad optical spectrum with topological features and wide edge modes

Long-range effective Hamiltonian explains the broad bandgaps

Presence of chiral squeezed fluctuations at edges in certain regimes

Abstract

We propose a scheme to realize a topological insulator with optical-passive elements, and analyze the effects of Kerr-nonlinearities in its topological behavior. In the linear regime, our design gives rise to an optical spectrum with topological features and where the bandwidths and bandgaps are dramatically broadened. The resulting edge modes cover a very wide frequency range. We relate this behavior to the fact that the effective Hamiltonian describing the system's amplitudes is long-range. We also develop a method to analyze the scheme in the presence of a Kerr medium. We assess robustness and stability of the topological features, and predict the presence of chiral squeezed fluctuations at the edges in some parameter regimes.