  Plasmonic antennas integrated on silicon devices have large and yet
unexplored potential for controlling and routing light signals. Here, we
present theoretical calculations of a hybrid silicon-metallic system in which a
single gold nanoantenna embedded in a single-mode silicon waveguide acts as a
resonance-driven filter. As a consequence of scattering and interference, when
the resonance condition of the antenna is met, the transmission drops by 85% in
the resonant frequency band. Firstly, we study analytically the interaction
between the propagating mode and the antenna by including radiative corrections
to the scattering process and the polarization of the waveguide walls.
Secondly, we find the configuration of maximum interaction and numerically
simulate a realistic nanoantenna in a silicon waveguide. The numerical
calculations show a large suppression of transmission and three times more
scattering than absorption, consequent with the analytical model. The system we
propose can be easily fabricated by standard silicon and plasmonic lithographic
methods, making it promising as real component in future optoelectronic
circuits.
