Multiple Tunable Hyperbolic Resonances in Broadband Infrared Carbon-Nanotube Metamaterials
Abstract
Aligned, densely-packed carbon nanotube metamaterials prepared using vacuum filtration are an emerging infrared nanophotonic material. We report multiple hyperbolic plasmon resonances, together spanning the mid-infrared, in individual resonators made from aligned and densely-packed carbon nanotubes. In the first near-field scanning optical microscopy (NSOM) imaging study of nanotube metamaterial resonators, we observe distinct deeply-subwavelength field profiles at the fundamental and higher-order resonant frequencies. The wafer-scale area of the nanotube metamaterials allows us to combine this near-field imaging with a systematic far-field spectroscopic study of the scaling properties of many resonator arrays. Thorough theoretical modeling agrees with these measurements and identifies the resonances as higher-order Fabry-P\'erot (FP) resonances of hyperbolic waveguide modes. Nanotube resonator arrays show broadband extinction from 1.5-10 {\mu}m and reversibly switchable extinction in the 3-5 {\mu}m atmospheric transparency window through the coexistence of multiple modes in individual ribbons. Broadband carbon nanotube metamaterials supporting multiple resonant modes are a promising candidate for ultracompact absorbers, tunable thermal emitters, and broadband sensors in the mid-infrared.
Keywords
Cite
@article{arxiv.2007.01970,
title = {Multiple Tunable Hyperbolic Resonances in Broadband Infrared Carbon-Nanotube Metamaterials},
author = {John Andris Roberts and Po-Hsun Ho and Shang-Jie Yu and Xiangjin Wu and Yue Luo and William L. Wilson and Abram L. Falk and Jonathan A. Fan},
journal= {arXiv preprint arXiv:2007.01970},
year = {2020}
}