Mapping plasmonic near-field profiles and interferences by surface-enhanced Raman scattering

Luping Du, Dangyuan Lei, Guanghui Yuan, Hui Fang, Xi Zhang, Qian Wang, Dingyuan Tang, Changjun Min, Stefan A. Maier, Xiaocong Yuan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

49 Citations (Scopus)

Abstract

Mapping near-field profiles and dynamics of surface plasmon polaritons is crucial for understanding their fundamental optical properties and designing miniaturized photonic devices. This requires a spatial resolution on the sub-wavelength scale because the effective polariton wavelength is shorter than free-space excitation wavelengths. Here by combining total internal reflection excitation with surface-enhanced Raman scattering imaging, we mapped at the sub-wavelength scale the spatial distribution of the dominant perpendicular component of surface plasmon fields in a metal nanoparticle-film system through spectrally selective and polarization-resolved excitation of the vertical gap mode. The lateral field-extension at the junction, which is determined by the gap-mode volume, is small enough to distinguish a spot size ∼0.355λ 0 generated by a focused radially polarized beam with high reproducibility. The same excitation and imaging schemes are also used to trace near-field nano-focusing and interferences of surface plasmon polaritons created by a variety of plasmon lenses.
Original languageEnglish
Article number3064
JournalScientific Reports
Volume3
DOIs
Publication statusPublished - 8 Nov 2013

ASJC Scopus subject areas

  • General

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