Excitation and imaging of resonant optical modes of Au triangular nanoantennas using cathodoluminescence spectroscopy

Anil Kumar, Kin Hung Fung, James C. Mabon, Edmond Chow, Nicholas X. Fang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

10 Citations (Scopus)

Abstract

Cathodoluminescence (CL) imaging spectroscopy is an important technique to understand the resonant behavior of optical nanoantennas. The authors report high-resolution CL spectroscopy of triangular gold nanoantennas designed with near-vacuum effective index and very small metal-substrate interface. This design helped in addressing issues related to background luminescence and shifting of dipole modes beyond visible spectrum. Spatial and spectral investigations of various plasmonic modes are reported. Out-of-plane dipole modes excited with a vertically illuminated electron beam showed high-contrast tip illumination in panchromatic imaging. By tilting the nanostructures during fabrication, in-plane dipole modes of antennas were excited. Finite-difference time-domain simulations for electron and optical excitations of different modes showed excellent agreement with experimental results. Their approach of efficiently exciting antenna modes by using low index substrates is confirmed both with experiments and numerical simulations. This should provide further insights into a better understanding of optical antennas for various applications.
Original languageEnglish
JournalJournal of Vacuum Science and Technology B:Nanotechnology and Microelectronics
Volume28
Issue number6
DOIs
Publication statusPublished - 1 Jan 2010
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Process Chemistry and Technology
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Electrical and Electronic Engineering

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