An Electrically Tunable Terahertz Filter Based on Liquid-Crystal-Filled Slits with Wall Corrugations

We propose a type of hollow planar waveguide with corrugated walls, which can realize electrically tunable terahertz (THz) filtering by filling the slit liquid crystals. When THz signals propagate in periodic corrugations, transmission spectrum always exhibits many pass and stop bands. Inserting section defects middle corrugations excite an extremely narrow peak, would be very good filter for frequency division. To achieve tunability this linewidth filter, we also fill between two walls nematic crystal. The effective refractive index crystals will change external electric field, thus tuning peak. simulated results show that center proposed tuned linearly range 0.984~1.023 field. Moreover, bandwidth adjusted from 3.2 GHz to 0.3 increasing number periods waveguide, maximum Q value 2556 achieved when at both sides defect is 12.