Plasmonic Archimedean Spiral Modes on Concentric Metal Ring Gratings
Yi-Chieh Lai1*, Yung-Chiang Lan1
1Department of Photonics, National Cheng Kung University, Tainan, Taiwan
* presenting author:Yi-Chieh Lai,
Plasmonic Archimedean spiral modes on the surface of concentric silver (Ag) ring gratings are investigated by FDTD simulations and theoretical analyses. These modes are excited by the single-stranded spiral surface plasmon (SP) mode on silver nanorod coupling onto the ring gratings. The observed spiral patterns are ascribable to propagation of SPs on Ag gratings with constant r and θ directional phase velocity.

Keywords: Archimedean spiral, Plasmonic, ring gratings, silver nanorod