Open AccessOrthogonal and parallel lattice plasmon resonance in core-shell SiO_2/Au nanocylinder arrays
Author(s) -
Linhan Lin,
Yasha Yi
Publication year - 2015
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.23.000130
Subject(s) - diffraction , plasmon , materials science , finite difference time domain method , optics , surface plasmon resonance , surface plasmon , substrate (aquarium) , optoelectronics , nanoparticle , physics , nanotechnology , oceanography , geology
Height induced coupling behavior between the plasmonic modes and diffraction orders were studied in the core-shell SiO(2)/Au nanocylinder arrays (NCAs) using finite difference time domain (FDTD) simulations. New lattice plasmon modes (LPMs) are observed in the structures with high aspect ratio. Specifically, parallel coupling between the plasmonic modes and diffraction orders is obtained here, which shows different coupling behavior from orthogonal LPMs. Electromagnetic (EM) field distributions indicate that horizontal propagation of the magnetic or electric field component is responsible for the generation of these orthogonal and parallel LPMs, respectively. Radiative loss could be effectively suppressed when the height increases. This is important for the applications of fluorescence enhancement and nano laser. Further studies confirm that the LPMs associated with the superstrate diffraction orders could be well maintained even when the Au coating is imperfect. The interference from the substrate associated LPMs could be eliminated by cutting off the corresponding diffraction waves by inducing a Si(3)N(4) substrate. This study of coupling behavior in the core-shell NCAs enables a novel route to design and optimize the LPMs for applications of bio-sensing and nano laser.