Brillouin and Kerr-based whispering gallery mode crystalline fluoride-type resonators for low noise microwave source

We report on Whispering Gallery mode resonators based on fluoride materials, MgF
₂
, BaF
₂
, CaF
₂
and LiF, under Stimulated Brillouin Scattering (SBS). We have simulated various fluoride material under various disc orientation. We have identified the specific orientation [111] in BaF
₂
as providing a low longitudinal wave velocity variation over the disc periphery, leading to a narrow line Brillouin frequency. Material influence is also pointed out under these configurations.