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.