Ultra-thin terahertz waveguides on periodic dielectric multilayers

We study theoretically, numerically and experimentally deeply sub-wavelength dielectric ridge terahertz waveguides on the surface of finite size photonic bandgap structures. We show that their dispersion relation can be described in a numerically stable closed form. We present the fundamental properties of surface modes on multilayers made of silicon and cyclo-olefin copolymer and study them experimentally. Several schemes for guiding terahertz light with surface modes in dielectric structures are illustrated.