Ultrabroadband nonreciprocal transverse energy flow of light in linear passive photonic circuits

TL;DR

This paper proposes a linear, passive photonic circuit that achieves ultrabroadband nonreciprocal transverse energy flow, breaking symmetry over an 80 nm wavelength range, with potential for integrated optical applications.

Contribution

It introduces a novel scheme for symmetry-breaking light propagation in linear passive waveguides, inspired by atomic physics techniques, with broad bandwidth and easy chip integration.

Findings

Achieves symmetry breaking over 80 nm bandwidth.

Uses only linear passive materials.

Compatible with integrated photonic circuits.

Abstract

Using a technique, analogous to coherent population trapping in an atomic system, we propose schemes to create transverse light propagation violating left-right symmetry in a photonic circuit consisting of three coupled waveguides. The frequency windows for the symmetry breaking of the left-right energy flow span over 80 nm. Our proposed system only uses linear passive optical materials and is easy to integrate on a chip.