A Scanning Fabry Perot Cavity for the Investigation of THz Frequency Magnon Polaritons

The formation of hybrid quasiparticles in strongly interacting light-matter systems is of increasing interest due to the potential applications as sensors or in other devices. Here we present the a scanning Fabry-Perot cavity designed to be used with a time-domain THz spectrometer to investigate the formation of polaritons that form as a result of coupling between cavity photons and samples stored inside the cavity. The cavity makes use of custom fabricated silicon Bragg reflectors to achieve a balance between overall transmission and high quality factor for the cavity. We will present initial results of the instrument applied in a search for coupling between THz photons and magnons.