Electromagnetic wave propagation through air-core waveguide with metamaterial cladding

Metamaterial-based waveguides offer unusual properties compared to conventional metallic and dielectric waveguides. We experimentally investigate a novel waveguide with an air-core and a cladding formed of slotted cylinder resonators, which can have an electric and/or a magnetic response at terahertz (THz) frequencies, depending on their orientation and the polarization of the light, and through these confine radiation to the hollow core. Various interesting phenomena are observed in the experiments, including confinement of radiation through the electric response as well as the magnetic response, spatial dispersion, total internal reflection with refractive indices below 1, and slit resonances. Such waveguides promise future novel THz applications, such as refractive index sensors or dispersion management.