Evaluation of the loaded and unloaded q-factors of traveling-wave whispering-gallery-mode resonators

A new graphical approach for evaluating the loaded and unloaded Q-factors of traveling-wave (TW) whispering-gallery-mode (WGM) resonators is proposed. This approach is based on extracting the attenuation and coupling coefficients of the resonator directly from the measured complex insertion loss values. The extracted Q-factor values of a measured K-band resonator are verified by using the well-known reaction method where rigorous results are obtained.