Exploring Coupled Plasmonic Nanostructures in the Near Field by Photoemission Electron Microscopy

Hiroaki Misawa, Yasutaka Matsuo, Atsushi Kubo, Tomoya Oshikiri, Kosei Ueno, Quan Sun, Yu Han

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

The extraordinary optical properties of coupled plasmonic nanostructures make these materials potentially useful in many applications; thus, they have received enormous attention in basic and applied research. Coupled plasmon modes have been characterized predominantly using far-field spectroscopy. In near-field spectroscopy, the spectral response of local field enhancement in coupled plasmonic nanostructures remains largely unexplored, especially experimentally. Here, we investigate the coupled gold dolmen nanostructures in the near field using photoemission electron microscopy, with wavelength tunable femtosecond laser pulses as an excitation source. The spatial evolution of near-field mapping of an individual dolmen structure with the excitation wavelength was successfully obtained. In the near field, we spatially resolved an anti-bonding mode and a bonding mode as the result of plasmon hybridization. Additionally, the quadrupole plasmon mode that could be involved in the formation of a Fano resonance was also revealed by spatially resolved near-field spectra, but it only contributed little to the total near-field enhancement. On the basis of these findings, we obtained a better understanding of the near-field nanostructures, where the plasmon hybridization and the plasmonic Fano resonance were mixed.
Original languageEnglish
Pages (from-to)10373-10381
Number of pages9
JournalACS Nano
Volume10
Issue number11
DOIs
StatePublished - Nov 2016

Keywords

  • near-field mapping; plasmon hybridization; Fano resonance; photoemission electron microscopy (PEEM); femtosecond laser pulses
  • ENHANCED PHOTOCURRENT GENERATION; FANO RESONANCE; VISIBLE-LIGHT; INFRARED WAVELENGTHS; RAMAN-SCATTERING; WATER OXIDATION; NANOPARTICLE; MODES; HYBRIDIZATION; NANOCLUSTERS

Fingerprint Dive into the research topics of 'Exploring Coupled Plasmonic Nanostructures in the Near Field by Photoemission Electron Microscopy'. Together they form a unique fingerprint.

Cite this