  Spoof surface waves are demonstrated theoretically to propagate along
periodic corrugated surfaces made of non-conductive lossless materials with
positive permittivity. An analytic derivation of the Spoof surface wave
dispersion relation is presented in the case of deeply subwavelength period of
a corrugated structure using impedance boundary conditions at the interfaces.
Thus obtained dispersion relation is verified numerically and limitations as
well as physicality of impedance boundary conditions when modeling Spoof
surface waves are discussed. Finally, suitable materials, potential
experimental realization, and sensing applications of Spoof surface waves in
the terahertz spectral range are discussed.
