Topological Sensing with Photonic Arrays of Resonant Circular Waveguides

TL;DR

This paper introduces a topological photonic sensor using resonant circular waveguides that detects trace chemicals with high sensitivity and robustness, leveraging topological edge modes impervious to disorder.

Contribution

It presents a novel design of a topological photonic sensor with subwavelength resonators that achieves high sensitivity and robustness for chemical detection.

Findings

Sensitivity scales linearly with system size.

Can detect chemicals at parts-per-billion levels.

Device remains robust despite disorder.

Abstract

We propose that a photonic array of resonant circular dielectric waveguides with subwavelength grating can be designed as a robust and sensitive topological chemical sensor. The device can detect trace amounts of a given chemical species through photonic edge modes that are impervious to most sources of disorder. We perform a simulation in the mid-infrared that accounts for the absorption loss introduced by chemical molecules in contact with a strongly coupled photonic lattice of resonators. Due to the topological nature of the device, its chemical sensitivity scales linearly with the system size and can reach parts-per-billion range at the millimeter scale. Our findings suggest that topological chemical sensors could empower the development of novel on-chip integrated photonic sensing technologies.