Three-dimensional Meta-atoms for High Confinement of Mid-IR Radiation

TL;DR

This paper introduces three-dimensional mid-infrared resonators with extreme field confinement, achieved through innovative design and characterization, promising advancements in sensing and nonlinear optics.

Contribution

First experimental demonstration and analytical modeling of 3D circuit-like resonators in the mid-IR with tunable resonant properties and high field confinement.

Findings

Successful fabrication and measurement of mid-IR 3D resonators

Precise control over resonant frequencies and losses

Demonstrated extreme electromagnetic field confinement

Abstract

The ability to confine photons into structures with highly sub-wavelength volumes is extremely interesting for many applications such as sensing, nonlinear optics, and strong light-matter interactions. However, their realization is increasingly difficult as the wavelength becomes shorter, due to fabrication challenges and increased metal losses. In this work, we present the first experimental characterization of three-dimensional circuit-like resonators operating in the mid-infrared. Through a combination of simulations, reflectivity measurements, and scanning near-field optical microscopy, we developed an analytical model capable of predicting the electromagnetic response of these structures based on their geometrical parameters. The design we studied offers a high degree of flexibility, enabling precise control over the resonant frequency of the various modes supported by the resonator, as well as independent control over radiative and non-radiative losses. Combined with the extreme field confinement demonstrated, these meta-atoms are highly promising for applications in detectors,