Localized surface plasmons selectively coupled to resonant light in tubular microcavities

TL;DR

This paper demonstrates selective coupling between resonant light in microtubular cavities and localized surface plasmons at nanogaps, revealing a new approach to studying light-matter interactions at micro- and nanoscale.

Contribution

It introduces a method to control coupling via nanogap placement on microtubes, supported by a modified quasi-potential model for explanation.

Findings

Selective coupling depends on nanogap location.

Coupling explained by a modified quasi-potential model.

Surface plasmon resonances couple to microcavity modes.

Abstract

Vertical gold-nanogaps are created on microtubular cavities to explore the coupling between resonant light supported by the microcavities and surface plasmons localized at the nanogaps. Selective coupling of optical axial modes and localized surface plasmons critically depends on the exact location of the gold-nanogap on the microcavities which is conveniently achieved by rolling-up specially designed thin dielectric films into three dimensional microtube ring resonators. The coupling phenomenon is explained by a modified quasi-potential model based on perturbation theory. Our work reveals the coupling of surface plasmon resonances localized at the nanoscale to optical resonances confined in microtubular cavities at the microscale, implying a promising strategy for the investigation of light-matter interactions.