Reconfigurable topological phases in next-nearest-neighbor coupled resonator lattices

TL;DR

This paper introduces a reconfigurable 2D topological photonic system using coupled resonator lattices that can switch between trivial and nontrivial phases via frequency detuning and external modulation, enabling advanced on-chip photon routing.

Contribution

The work presents a novel, translationally invariant resonator lattice design that realizes reconfigurable topological phases through next-nearest-neighbor couplings with controllable phases.

Findings

Demonstrates topological phase transition controlled by frequency detuning.

Designs reconfigurable topological waveguides for photon routing.

System can be tuned via thermal, electro-optic, or nonlinear effects.

Abstract

We present a reconfigurable topological photonic system consisting of a 2D lattice of coupled ring resonators, with two sublattices of site rings coupled by link rings, which can be accurately described by a tight-binding model. Unlike previous coupled-ring topological models, the design is translationally invariant, similar to the Haldane model, and the nontrivial topology is a result of next-nearest couplings with non-zero staggered phases. The system exhibits a topological phase transition between trivial and spin Chern insulator phases when the sublattices are frequency detuned. Such topological phase transitions can be easily induced by thermal or electro-optic modulators, or nonlinear cross phase modulation. We use this lattice to design reconfigurable topological waveguides, with potential applications in on-chip photon routing and switching.