Gold nanoparticle absorption under a nanoscale tip illuminated by surface-plasmon polaritons

Gazi M. Huda, J. Todd Hastings

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


This research numerically calculated the optical absorption of gold nanoparticles (AuNP) in the presence of metallic (Au) and dielectric (Si) AFM probes, illuminated by a surface plasmon polaritons on an infinite gold substrate. Nanoscale probes localize and enhance the field between the apex of the tip and the particle. However, the absorption of the nanoparticle is not always enhanced; in fact, under a gold tip, the absorption is suppressed for a 50 nm diameter AuNP. After fitting the numerical absorption data with the equation of a driven damped harmonic oscillator (HO), it was found that the AFM tip modifies both the driving force (F0), consisting of the free carrier charge (q) and the driving field (E), and the overall damping of the oscillator (β). The enhancement or suppression of absorption with different tips can be understood in terms of competition between β and F 0. Introducing the metallic tip increases β and decreases F 0, resulting in reduced absorption. Introducing the dielectric tip, although it increases β,it also increases F0, resulting in overall absorption enhancement. Therefore, one most consider both β and F0 to control the absorption of nanoparticles under Surface Plasmon Polaritons.

Original languageEnglish
Title of host publicationPhysics and Simulation of Optoelectronic Devices XXI
StatePublished - 2013
EventPhysics and Simulation of Optoelectronic Devices XXI - San Francisco, CA, United States
Duration: Feb 4 2013Feb 7 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferencePhysics and Simulation of Optoelectronic Devices XXI
Country/TerritoryUnited States
CitySan Francisco, CA


  • AFM probe
  • evanescent wave
  • finite element method
  • harmonic oscillator
  • optical absorption
  • plasmonics
  • propagating surface plasmon

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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