3D Confocal Raman Tomography to Probe Field Enhancements inside Supercluster Metamaterials
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Spherical colloidal superclusters, composed from sub-100 nm plasmonic nanoparticles, have been proposed to possess collective plasmonic modes imbued with large field enhancements and tunable spectral response extending from the visible to infrared regions. Here, we report the experimental verification of collective near-IR plasmonic modes inside single superclusters, with dimensions ranging from 0.77 μm up to 2 μm. Raman reporters, coated onto the nanoparticle building blocks, were used as local probes of the electric field enhancement inside the metamaterial. By performing diffraction-limited 3D Raman tomography we were able to build up the electric field intensity distribution within the superclusters. We demonstrate that plasmonic responses of superclusters vary according to their size and excitation wavelength, in accordance with theoretical predictions of their tunable optical properties. The existence of three-dimensional internal collective modes in these superclusters enables the excitation of a large number of electromagnetic hot-spots, validating these self-assembled structures as promising candidates for molecular spectroscopy.
Date Issued
2017-08-16
Date Acceptance
2017-07-06
Citation
ACS Photonics, 2017, 4 (8), pp.2070-2077
ISSN
2330-4022
Publisher
American Chemical Society
Start Page
2070
End Page
2077
Journal / Book Title
ACS Photonics
Volume
4
Issue
8
Copyright Statement
This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://dx.doi.org/10.1021/acsphotonics.7b00504
Sponsor
Commission of the European Communities
Engineering & Physical Science Research Council (EPSRC)
Commission of the European Communities
Engineering & Physical Science Research Council (EPSRC)
Commission of the European Communities
Grant Number
279818
EP/L02098X/1
658544
EP/P011985/1
724300
Publication Status
Published