Theoretical Investigation of Phonon Polaritons in SiC Micropillar Resonators

TL;DR

This paper provides a comprehensive theoretical analysis of phonon polariton resonators made of SiC micropillars, elucidating the coupling mechanisms between localized and propagative modes to advance mid-infrared nanophotonics.

Contribution

It introduces a combined numerical and analytical approach to understand the resonances of SiC micropillar resonators on substrates, enhancing the theoretical foundation of this technology.

Findings

Identified the coupling mechanisms between localized and propagative phonon polaritons.

Mapped the parameter space for SiC micropillar resonators.

Provided analytical models aligning with numerical simulations.

Abstract

Of late there has been a surge of interest in localised phonon polariton resonators which allow for sub-diffraction confinement of light in the mid-infrared spectral region by coupling to optical phonons at the surface of polar dielectrics. Resonators are generally etched on deep substrates which support propagative surface phonon polariton resonances. Recent experimental work has shown that understanding the coupling between localised and propagative surface phonon polaritons in these systems is vital to correctly describe the system resonances. In this paper we comprehensively investigate resonators composed of arrays of cylindrical SiC resonators on SiC substrates. Our bottom-up approach, starting from the resonances of single, free standing cylinders and isolated substrates, and exploiting both numerical and analytical techniques, allows us to develop a consistent understanding of the parameter space of those resonators, putting on firmer ground this blossoming technology.