Open AccessConstructive-interference-enhanced Fano resonance of silver plasmonic heptamers with a substrate mirror: a numerical study
Author(s) -
Xing Zhu,
Huimin Shi,
Shi Zhang,
Quanhui Liu,
Huigao Duan
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.009938
Subject(s) - fano resonance , plasmon , fano plane , optics , materials science , substrate (aquarium) , surface plasmon resonance , optoelectronics , resonance (particle physics) , silicon , metamaterial , nanotechnology , physics , nanoparticle , geometry , oceanography , mathematics , particle physics , geology
Plasmonic nanostructures with strong Fano resonance are of fundamental interest. Here, our systematic simulations show that rational positioning of a silver plasmonic heptamer above a highly reflective substrate mirror can significantly enhance its intrinsic Fano-resonance intensity. The silver nanodisk heptamer positioned at an appropriate distance above the reflective substrate enables 2.4 times field enhancement and 3.6 times deeper Fano-dip respectively compared to the heptamer directly placed on silicon oxide substrate. Besides, our results indicate that the Fano-dip position does not shift when the silver nanodisk heptamer gradually shifts away from the reflective substrate mirror (≥60 nm).