Enhancing the Reception of Propagating Surface Plasmons Using a Nanoantenna

We present a technique to efficiently receive electromagnetic fields from a metal-insulator-metal waveguide using a dipole nanoantenna formed by two nanorods. The received fields are strongly enhanced in a nanocavity, also created by the two nanorods, via localized surface plasmon effects. The averaged or volume-integration of the electric field intensity in the nanocavity can be maximized by optimizing the geometry of the nanorods, the gap distance between the two nanorods, as well as the optical properties of the materials inside the nanocavity. The proposed technique may find applications in the design of plasmonic photodetectors, switches, and sensors.