jp4004054_si_001.pdf (140.21 kB)
Two-Step Decomposition of Plasmon Coupling in Plasmonic Oligomers
journal contribution
posted on 2013-06-06, 00:00 authored by Meng Wang, Min Cao, Zhirui Guo, Ning GuPlasmon coupling in plasmonic oligomers
gives rise to many unique
optical properties including electromagnetically induced transparency
and Fano resonances. Controlling over the optical properties of plasmonic
oligomers requires a deep understanding of the physical mechanisms.
Herein, we first examine the near and far field optical properties
of silver pentamer by the coupled dipole approximation. It is shown
that the Fano-like resonance in the pentamer is analogous to the spectrum
of a heterogeneous plasmonic dimer. Therefore, we propose a subgroup
decomposition method for predicting the spectrum profiles of the oligomers.
In the decomposition procedure, the oligomer is divided into simple
subgroups in terms of the arrangement of nanoparticles and incident
polarization, and the optical response of the oligomer is determined
by the coupling of the subgroups. We further investigate its validity
in strongly coupled plasmonic oligomers through the generalized multiparticle
Mie solution. The optical properties of the close-packed oligomers
can also be easily modulated by means of the decomposition method,
which provides a flexible tool for the optimal design of plasmonic
nanostructures.