THz wave transmission within the metal film coated double-dielectric-slab waveguides and the tunable filter application

We propose a metal film coated double-dielectric-slab waveguide for guiding THz wave. Detailed comparisons of transmission characteristics of the coated and uncoated double-dielectric-slab waveguides are given. The comparisons of different slab materials are also given. We put forward using the measureable cut-off frequency of the coated waveguides for tunable filter. The tunable sensitivities to the thickness of the slab t and the air interval w are discussed. We find that for Polystyrene slab at t=0.0380 mm, the theoretical tunable sensitivity of cut-off frequency on w can be 7.65 THz/mm.