Non-local scattering control in coupled resonator networks

TL;DR

This paper presents a method to control scattering of Gaussian wave packets in coupled resonator optical waveguides using an external resonator, enabling functionalities like trapping, splitting, and interferometry with analytical and numerical validation.

Contribution

It introduces a novel approach for non-local scattering control in coupled resonator networks using an external resonator, with analytical formulas and practical configurations demonstrated.

Findings

Effective light trapping with exponential decay

Wave packet splitting into identical parts

Implementation of a non-local Mach-Zehnder interferometer

Abstract

We demonstrate scattering control of Gaussian-like wave packets propagating with constant envelope velocity and invariant waist through coupled resonator optical waveguides (CROW) via an external resonator coupled to multiple sites of the CROW. We calculate the analytical reflectance and transmittance using standard scattering methods from waveguide quantum electrodynamics and show it is possible to approximate them for an external resonator detuned to the CROW. Our analytical and approximate results are in good agreement with numerical simulations. We engineer various configurations using an external resonator coupled to two sites of a CROW to show light trapping with effective exponential decay between the coupling sites, wave packet splitting into two pairs of identical Gaussian-like wave packets, and a non-local Mach-Zehnder interferometer.