Abstract
ABSTRACT:Plasmonic gap modes provide the ultimateconfinement of opticalfields. Demanding high spatialresolution, the direct imaging of these modes was onlyrecently achieved by electron energy loss spectroscopy (EELS)in a scanning transmission electron microscope (STEM).However, conventional 2D STEM-EELS is only sensitive tocomponents of the photonic local density of states (LDOS)parallel to the electron trajectory. It is thus insensitive tospecific gap modes, a restriction that was lifted with the introduction of tomographic 3D EELS imaging. Here, we show that by3D EELS tomography the gap mode LDOS of a vertically stacked nanotriangle dimer can be fully imaged. Besides probing thecomplete mode spectrum, we demonstrate that the tomographic approach allows disentangling the signal contributions from thetwo nanotriangles that superimpose in a single measurement with afixed electron trajectory. Generally, vertically couplednanoparticles enable the tailoring of 3D plasmonicfields, and their full characterization will thus aid the development of complexnanophotonic devices.
Originalsprache | englisch |
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Seiten (von - bis) | 6773-6777 |
Fachzeitschrift | Nano Letters |
Jahrgang | 2017 |
Ausgabenummer | 17 |
DOIs | |
Publikationsstatus | Veröffentlicht - 2017 |
ASJC Scopus subject areas
- Werkstoffwissenschaften (insg.)
Fields of Expertise
- Advanced Materials Science
Treatment code (Nähere Zuordnung)
- Application
Kooperationen
- NAWI Graz