Metal plate for guiding terahertz surface plasmon-polaritons and its sensing applications

We report the guiding of THz surface plasmon-polaritons using metal plates. We theoretically study the transmission characteristics of the bare and dielectric coated metal plate and compared the difference between them. We propose coupling the THz SPPs on a bare metal plate using single dielectric film, and the highest theory coupling efficiency we get can be 45.64%. Moreover we study the hybrid plasmonic modes of a dielectric slab above the metal plate, and we find that the THz SPPs on metal plate is strongly affected by the dielectric slab. We further discuss the interesting phenomenon of the transmission spectrum influenced by the variation of air interval between the dielectric slab and metal plate.