Terahertz wedge plasmon polaritons.

We propose a metamaterial approach to route terahertz waves that features subwavelength confinement in the transverse plane. The guiding mechanism is based on geometrically induced electromagnetic modes sustained by corrugated metallic wedges, whose characteristics resemble those of wedge plasmon polaritons at telecom and optical frequencies. Additionally, frequency selective focusing and slowing down of terahertz radiation based on the proposed wedge waveguides are presented.