Broadband optical nonreciprocity via nonreciprocal band structure

TL;DR

This paper proposes a one-dimensional optomechanical array that leverages nonreciprocal band structure to achieve broadband optical nonreciprocity with high isolation, advancing on-chip optical isolator technology.

Contribution

It introduces a novel approach using nonreciprocal band structure in Brillouin optomechanical lattices for broadband, high-isolation optical nonreciprocity.

Findings

Demonstrates broadband optical nonreciprocity with high isolation.

Shows nonreciprocal band structure can be achieved via stimulated Brillouin scattering.

Proposes optomechanical arrays as a platform for nonreciprocal effects.

Abstract

As a promising approach for optical nonreciprocity without magnetic materials, optomechanically induced nonreciprocity has great potential for all-optical controllable isolators and circulators on chips. However, as a very important issue in practical applications, the bandwidth for nonreciprocal transmission with high isolation has not been fully investigated yet. In this study we review the nonreciprocity in a Brillouin optomechanical system with single cavity and point out the challenge in achieving broad bandwidth with high isolation. To overcome this challenge, we propose a one dimensional optomechanical array to realize broadband optical nonreciprocity via nonreciprocal band structure. We exploit nonreciprocal band structure by the stimulated Brillouin scattering induced transparency with directional optical pumping, and show that it is possible to demonstrate optical nonreciprocity with both broad bandwidth and high isolation. Such Brillouin optomechanical lattices with nonreciprocal band structure, offer an avenue to explore nonreciprocal collective effects in different electromagnetic and mechanical frequency regimes, such as nonreciprocal topological photonic and phononic phases.