Surface plasmon polariton modes in a single-crystal Au nanoresonator fabricated using focused-ion-beam milling

TL;DR

This study demonstrates the fabrication and imaging of highly localized surface plasmon modes in a single-crystal gold nanoresonator created via focused-ion-beam milling, highlighting a rapid prototyping method for nanoscale plasmonic devices.

Contribution

It introduces a novel fabrication technique for single-crystal gold nanoresonators and confirms their ability to support localized surface plasmon modes using cathodoluminescence spectroscopy.

Findings

Support for highly localized plasmon modes (<100 nm)

Effective fabrication of nanoresonators using focused-ion-beam

Potential for rapid prototyping of plasmonic components

Abstract

We use focused-ion-beam milling of a single-crystal Au surface to fabricate a 590-nm-long linear ridge that acts as a surface plasmon nanoresonator. Cathodoluminescence imaging spectroscopy is then used to excite and image surface plasmons on the ridge. Principal component analysis reveals distinct plasmonic modes, which proves confinement of surface-plasmon oscillations to the ridge. Boundary-element-method calculations confirm that a linear ridge is able to support highly-localized surface-plasmon modes (mode diameter < 100 nm). The results demonstrate that focused-ion-beam milling can be used in rapid prototyping of nanoscale single-crystal plasmonic components.