Evidence of THz surface plasmon-like wave propagation along a 1D metallic grid

We study the transmission, in the THz domain, of a metallic grid deposited over a high resistivity silicon substrate. By analyzing the transmission spectra recorded for different angles of incidence, we identify each guided mode of the structure. The p-polarized modes show a behavior that is intermediate between those of surface plasmon along the metal and of guided mode in the substrate.