Spatially switched near field distribution using plasmonic random nanoislands

Gwiyeong Moon, Taehwang Son, Hongki Lee, Donghyun Kim

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We investigate switching near-field distribution on metal random nanoislands by changing the direction and the angle of light incidence in 14 channel modes. Distribution of the near-fields induced by different channel modes was calculated by finite difference time domain method. The size of near-fields under oblique channel modes ranges 48 - 77 nm in contrast to 127 - 145 nm with normal incidence. Quantitative analysis of near-field position was performed relative to nanoislands. Near-field position was largely well aligned with the direction of incident channel modes. Switching near fields was experimentally confirmed in two ways, first by measurement of fluorescence intensity and by NSOM. Fluorescence experiment was conducted by using bare glass substrate and gold nanoislands in seven channel modes. Fluorescence intensity on bare glass substrate shows symmetric intensity changes with channel modes. However, fluorescence intensity on gold nanoislands was found to be asymmetric. For quantitative analysis, mean-squared error (MSE) was calculated by defining fluorescence intensity as a 7D vector. Distribution of MSE in case of gold nanoislands was broader than on bare glass substrate. In other words, near fields induced on gold nanoislands were switched more strongly than bare glass substrate. Also, near fields induced on nanoislands were measured directly using NSOM in two channel modes. It was confirmed that spatial positions of near-fields depend on channel modes. The results of this study suggest that the near fields can be controlled by adjusting channel modes, which opens possibilities of highly sensitive and super-resolved detection and imaging.

Original languageEnglish
Title of host publicationPlasmonics in Biology and Medicine XVI
EditorsTuan Vo-Dinh, Ho-Pui A. Ho, Krishanu Ray
ISBN (Electronic)9781510624306
Publication statusPublished - 2019
EventPlasmonics in Biology and Medicine XVI 2019 - San Francisco, United States
Duration: 2019 Feb 32019 Feb 5

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferencePlasmonics in Biology and Medicine XVI 2019
Country/TerritoryUnited States
CitySan Francisco

Bibliographical note

Publisher Copyright:
© 2019 SPIE.

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging
  • Biomaterials


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