Investigation of the Optical Properties of Silicon-on-Insulator Microring Resonators Using Optical Backscatter Reflectometry

Abstract

Introduction. Optical backscatter reflectometry is one of the most promising methods used to examine characteristic parameters relevant to the design of microring resonators. This method paves the way for experimental determination of the coupling coefficient and propagation loss. However, experimental verification of this technique by comparing the transmission characteristics obtained by reflectometry and those directly measured by an optical vector analyzer has not been carried out.Aim. To determine the parameters of microring resonators by optical reflectometry and to calculate on their basis the transmission characteristics of microring resonators. To compare the calculated transmission characteristics with those obtained experimentally using a high-resolution vector analyzer.Materials and methods. The characteristic parameters of silicon-on-insulator microring resonators were investigated using an ultra-high resolution reflectometer. An original algorithm was employed to derive the characteristic parameters of microring resonators from reflectograms. An optical vector analyzer was used to study the transmission characteristics of microring resonators. Numerical modeling of transmission characteristics considering the obtained parameters was carried out according an analytical approach based on partial wave analysis.Results. The obtained values of the power coupling coefficient κ = 0.167 and propagation losses α = 3.25 dB/cm were used for numerical simulation of the transmission characteristics of a microring resonator. These characteristics were found to agree well with those obtained experimentally. The free spectral range of 88.8 GHz and Q-factor of 45 000 were determined.Conclusion. An experimental study of the characteristic parameters of silicon-on-insulator microring resonators was conducted using an optical backscatter reflectometer. The performed comparison of the experimental and theoretical transmission characteristics showed good agreement, which indicates the high accuracy of the determined resonator parameters and, as a result, the relevance of the described method.