Self-similar gold-nanoparticle antennas for a cascaded enhancement of the optical field

Phys Rev Lett. 2012 Jul 6;109(1):017402. doi: 10.1103/PhysRevLett.109.017402. Epub 2012 Jul 6.

Abstract

We experimentally demonstrate cascaded field enhancement by means of gold nanoparticle dimer and trimer antennas. The local field enhancement is probed by single-molecule fluorescence using fluorophores with high intrinsic quantum efficiency (Q(0)>80%). Using a self-similar trimer antenna consisting of 80, 40, and 20 nm gold nanoparticles, we demonstrate a fluorescence enhancement of 40 and a spatial confinement of 15 nm. Compared with a single gold nanoparticle, the self-similar trimer antenna improves the enhancement-confinement ratio by more than an order of magnitude. Self-similar antennas hold promise for high-resolution imaging and spectroscopy, ultrasensitive detection, and efficient single-photon sources.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Fluorescent Dyes / chemistry
  • Gold / chemistry*
  • Metal Nanoparticles / chemistry*
  • Models, Theoretical*
  • Optics and Photonics / instrumentation*
  • Optics and Photonics / methods*
  • Oxazines / chemistry
  • Quantum Theory
  • Spectrometry, Fluorescence / instrumentation
  • Spectrometry, Fluorescence / methods

Substances

  • Fluorescent Dyes
  • Oxazines
  • Nile Blue
  • Gold