A 2-D Artificial Dielectric With 0 ≤ n < 1 for the Terahertz Region

We demonstrate a 2-D artificial dielectric medium suitable for the terahertz region by exploiting the characteristic frequency dependence in the phase velocity of the lowest order transverse-electric (TE(1)) mode of the parallel-plate waveguide (PPWG). This artificial medium exhibits a plasma-like behavior having a frequency-dependent refractive index that varies between zero and unity. Using this medium, we demonstrate the optical phenomena of total internal reflection and Brewster's effect, and also demonstrate a convergent PPWG-lens.