Topological photonic crystal fibers and ring resonators

TL;DR

This paper explores topological features in photonic crystal fibers and ring resonators, demonstrating robust edge states and energy localization due to topological protection, which could enhance optical device performance.

Contribution

It introduces topological photonic structures with Aubry-Andre-Harper modulations, showing their robustness and unique field localization compared to conventional devices.

Findings

Presence of non-trivial gaps and edge states at interfaces with different Chern numbers

Topological protection leads to robustness against local perturbations

Strong field localization and energy concentration in the structures

Abstract

We study photonic crystal fibers and ring resonators with topological features induced by Aubry- Andre-Harper modulations of the cladding. We find non trivial gaps and edge states at the interface between regions with different Chern numbers. We calculate the field profile and eigenvalue dispersion by an exact recursive approach. Compared with conventional circular resonators and fibers, the proposed structure features topological protection and hence robustness against symmetry-preserving local perturbations that do not close the gap. These topological photonic crystal fibers sustain strong field localization and energy concentration at a given radial distance. As topological light guiding and trapping devices, they may bring about many opportunities for both fundamentals and applications unachievable with conventional optical devices.