| AVS 54th International Symposium | |
| Plasmonics Topical Conference | Monday Sessions |
| Session PL-MoM |
| Session: | Plasmonic Nanostructures and Plasmon Manipulation |
| Presenter: | K. Tamada, Tokyo Institute of Technology, Japan |
| Authors: | K. Tamada, Tokyo Institute of Technology, Japan K. Michioka, Tokyo Institute of Technology, Japan X. Li, Tokyo Institute of Technology, Japan Y. Ikezoe, Tokyo Institute of Technology, Japan M. Hara, Tokyo Institute of Technology, Japan |
| Correspondent: | Click to Email |
In this paper, we present our latest result concerning the coupling between propagating surface plasmon on flat gold surface and local plasmon on silver nanoparticles. The silver nanoparticles are deposited on the substrate as 'nano-sheet' composed of two dimensional crystalline layer fabricated at air-water interface, in which the distance between the particle cores is controlled accurately by the thickness of the shell layer and the compressions (e.g., core diameter: 3.7nm, core distance between neighboring particles : 6.6nm). We found the silver nano-sheet deposited on glass to exhibit a significant shift of plasmon absorption band in UV-vis-Near-IR spectra to the longer wavelength (c.a. 50nm), while the peak width was rather reduced (sharpened) in the sheet formation. We determined the dielectric constant of the silver nano-sheet by Kramers-Kronig analyses of the UV-vis-Near-IR spectra, and compared with the value obtained from the SPR angle shift on gold substrate. The SPR curves are broadened distinctively depending on the thickness of sandwiched dielectric layer (in our study, alkanethiol self-assembled monolayers or Langmuir-Blodget films are utilized to control the distance between the nano-sheet and the gold substrate), which evidences the dipole coupling between the gold substrate and the silver nano-sheet. By use of this ideal nanostructual material, we examined several fundamental issues concerning the propagating and the local surface plasmons and their coupling effect on the optical responses.