Terahertz surface plasmon polaritons propagation in slanted pillar geometries

Abstract

In this paper, we present detailed numerical study of periodically corrugated surfaces to establish the directional dependence of terahertz (THz) surface plasmon polaritons propagation. A metal surface approximated as perfectly electrical conductor at terahertz frequencies, is periodically patterned with slanted sub-wavelength scale pillars forming a plasmonic waveguide. The slanted pillar geometries are found to support highly confined terahertz modes at specific frequencies which can be tailored with the slanted pillar parameters and their angle of tilt with respect to the normal. The terahertz mode propagation with different angles through which pillars are tilted w.r.t. the normal is examined in detail. From these results we observed that the slanted geometries are more efficient in guiding terahertz in a particular direction.