Optimizing contact area geometry and taper composition in microknot resonators

We performed a comprehensive numerical study of the photonic transmission in manually prepared microknot resonators with different contact coupling area geometries and refractive index variations. A quantitative comparison between historical and state-of-the-art quality-factor values achieved in microring, microloop, and microknot resonators is included. In selective modifications of the microknot coupling area shape and the refractive index profile, we have studied the microknot transmission characteristics. A recipe for the experimental realization of a 4-fold increase of values in microknot resonators is prescribed, where resonance parameters are beneficial for sensing applications, both in physical (temperature and refractive index) and in chemical (humidity and other gas components) characterizations.