Active control of terahertz waves based on hybrid VO periodic corrugated waveguides.

We describe a method for the active control of terahertz (THz) waves using hybrid vanadium dioxide (VO) periodic corrugated waveguide. Unlike liquid crystals, graphene and semiconductors and other active materials, VO exhibits a unique insulator-metal transition characteristic by the electric fields, optical, and thermal pumps, resulting in five orders of magnitude changes in its conductivity. Our waveguide consists of two gold coated plates with the VO-embedded periodic grooves, which are placed in parallel with the grooves face to face. Simulations show that this waveguide can realize mode switching by changing the conductivity of the embedded VO pads, whose mechanism is attributed to the local resonance induced by defect mode. Such a VO-embedded hybrid THz waveguide is favorable in practical applications such as THz modulators, sensors and optical switches, and provides an innovative technique for manipulating THz waves.