標題: Exploring Coupled Plasmonic Nanostructures in the Near Field by Photoemission Electron Microscopy
作者: Yu, Han
Sun, Quan
Ueno, Kosei
Oshikiri, Tomoya
Kubo, Atsushi
Matsuo, Yasutaka
Misawa, Hiroaki
應用化學系
應用化學系分子科學碩博班
Department of Applied Chemistry
Institute of Molecular science
關鍵字: near-field mapping;plasmon hybridization;Fano resonance;photoemission electron microscopy (PEEM);femtosecond laser pulses
公開日期: Nov-2016
摘要: 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.
URI: http://dx.doi.org/10.1021/acsnano.6b06206
http://hdl.handle.net/11536/132842
ISSN: 1936-0851
DOI: 10.1021/acsnano.6b06206
期刊: ACS NANO
Volume: 10
Issue: 11
起始頁: 10373
結束頁: 10381
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