A new ring resonator design based on Bragg reflectors is presented. The resonator implements the fundamental TE01gamma mode in a cylindrical sapphire dielectric, which is confined by the addition of radial and axial sapphire Bragg reflectors. It is shown that an unloaded Q-factor of 187000 can be obtained for a frequency near 9 GHz.
Piquet, O., Laporte, A., Cros, D., Verdeyme, S., & Tobar, M. (2003). High-Q sapphire resonator with distributed Bragg reflectors. Electronics Letters, 39(25), online - approx 5-10pp. https://doi.org/10.1049/el:20031169