Waveguide coupling to high index whispering gallery mode resonators in the THz domain

Whispering gallery mode (WGM) resonators have high Q factors and small modal volumes and can thus show strong non-linear interactions. Most of the interesting non-linear materials are crystalline and feature high refractive indices such that efficient coupling to the resonator is challenging. We present a study on high refractive index WGM resonators and show that coupling via a crystalline dielectric rod waveguide is possible.