New methodology to evaluate the performance of ring resonators using optical low-coherence reflectometry

This paper describes the efficient implementation of optical low-coherence reflectometry (OLCR) measurements to evaluate the performance of InP-based high-index contrast ring resonators. Using examples of racetrack ring resonators, this paper shows here for the first time that all characteristic parameters relevant to resonator design (coupling coefficient re, propagation losses a, and optical cavity length L), and ultimately its performance, can be extracted in a straightforward manner. This is accomplished by introducing a new methodology that implicates OLCR measurements in transmission and also reflection modes as an alternative approach, in comparison with conventional spectral analysis, to extract resonator design parameters.