Abstract
We show that spoof surface plasmons can be used to control the reflection of terahertz radiation at the output facet of a parallel-plate waveguide. Using a periodic groove pattern on the output face, reflectivity approaching 100 can be achieved within a limited spectral range. Unlike the conventional geometry for plasmon-enhanced transmission, this approach enables a unique method for studying the coupling between the guided mode and the surface plasmon through angle-dependent measurement of the plasmon-mediated reflection. A simple model incorporating the surface plasmon coupling to the waveguide mode can adequately explain all of the observed phenomena, including the observed Goos-Hänchen shift in the reflected beam.
- Received 17 September 2012
DOI:https://doi.org/10.1103/PhysRevB.86.241405
©2012 American Physical Society