Detecting THz in the telecom range: All resonant THz up-conversion in a whispering gallery mode resonator

Coherent detection of very weak THz signals is important in astronomy, spectroscopy, and communications. We report on coherent up-conversion of THz radiation into the optical telecommunication range. All resonant phase-matched conversion can be achieved in a whispering gallery mode (WGM) resonator. Furthermore we present first results on WGM resonators that can be coupled to both THz radiation as well as optical fields allowing the study of non-linear interactions between the two frequency domains.