Terahertz surface plasmon on semiconductor and thin dielectric surfaces

We theoretically study the properties of terahertz (THz) surface plasmon (SP) propagating on semiconductor and thin dielectric surfaces by employing numerical calculations. The results show that the major energy of THz SP can be confined in the thin film on the surface of an InSb semiconductor. At the same time, the magnetic field dispersion curves and absorption coefficients of the structures are studied. We find that the absorption coefficient is related to the permittivity of the dielectric films. Therefore, we can sensitively detect a thin dielectric sample by broadband terahertz spectroscopy.