Multi-parameter estimation of high-Q silicon rich nitride resonators using optical frequency domain reflectometry

Many linear and nonlinear optics applications rely on micro-resonators (MRRs) with carefully designed dispersion and coupling rate coefficients. These parameters are however challenging to measure for MRRs based on high-confinement optical waveguides. In this paper, we report on the use of optical frequency domain reflectometry (OFDR) for the measurement of group velocity dispersion (GVD), coupling coefficients and round-Trip loss, in high-Q (Q i ∼ 0.3 × 10 6 ) silicon-rich nitride MRRs. This technique allows for retrieving the GVD coefficients, intrinsic losses and coupling coefficients for each transverse mode in the resonator, thus providing very valuable feed-back information from experiments to the design flow step.