Determination of coupling regime of high-Q coupled resonators using cavity ring down spectroscopy

摘要

We implement a mathematical model able to predict the amplitude variation of the optical field inside a coupled high-Q resonator as a function of the scanning wavelength. Similarly to a Fabry-Perot cavity with its two highly reflecting mirrors, the resonator has two fiber based tap couplers. By fitting experimental data with this model, it is possible to determine the physical characteristics of the resonator, such as Q-factor, coupling coefficients, and coupling regimes. In order to test our modelling tool we applied it to characterize a fiber ring resonator in add-drop configuration. We also perform preliminary test on a high-Q whispering gallery mode optical disk resonators.