Affiliations: [a] Laboratory of Applied Electromagnetism, Federal
University of Para, Belem, Brazil | [b] Military Institute of Engineering, Rio de Janeiro,
Brazil
Correspondence:
[*]
Corresponding author: Anderson O. Silva, UFPA-LEA (Laboratory of
Applied Electromagnetism – Federal University of Para), C. U. Jose da Silveira
Neto – 66075-110, Belem, Brazil. Tel.: +55 91 3201 7740; E-mail:
aosilva@ufpa.br
Abstract: Surface plasmon-polariton excitations are electromagnetic modes
responsible for a huge field confinement at the interface between a conductor
and a dielectric. These modes mitigate light scattering even below the
diffraction limit, which allows the reduction in size of several kinds of
electromagnetic devices such as waveguides, resonators and sensors. Within this
framework, we apply the FEM-RBCI formulation to investigate the response at the
optical spectrum of a nanocavity filled with silver nanodisks. Computational
simulations show that the coupling between localized surface plasmon modes
excited at the periphery of the nanodisks yields a high sensitivity degree in
an ultra-compact area. Such sensitivity is nearly constant and covers a wide
range of refraction indexes of the surrounding medium. Furthermore, it is not
required any external phase matching technique to achieve surface plasmon
resonance. These characteristics demonstrates the great potential of the
structure to improve optical sensing applications.
