Magnetic polariton-based thermal emitter for dual-band filterless gas sensing

TL;DR

This paper introduces a compact, dual-band thermal emitter based on metasurfaces that enables filterless gas sensing, specifically improving CO2 detection sensitivity without bulky optical components.

Contribution

The work presents a novel metasurface design supporting magnetic polariton modes for dual-band, directional thermal emission, eliminating the need for optical filters in infrared gas sensors.

Findings

CO2 sensing sensitivity is 3.2 times higher than blackbody emission.

The emitter's temperature sensitivity is approximately 1.32% per Kelvin.

The metasurface supports two nondispersive magnetic polariton modes with distinct emission profiles.

Abstract

The miniaturization of infrared gas sensors is largely hindered by expensive and bulky laser sources as well as the use of optical filters. In this work, we propose a dual-band, directional thermal emitter based on compact W-Si-Cu metasurfaces to address this issue. This metasurface emitter is designed to support two nondispersive magnetic polariton modes that exhibit distinct directional thermal emission profiles, thus enabling dual-band detection without the need of optical filters. Specifically, we evaluate the feasibility of such dual-band filterless detection by adapting the metasurface emitter to CO2 sensing. The model of sensing system shows a selective relative sensitivity of CO2 which is 3.2 times higher than that using a blackbody emitter, and a relative sensitivity of temperature of emitter about 1.32%/K.