Coupling coefficient increment and free spectral range decrement by proper design of microring resonator parameters

Effects of different structural parameters on the optical characteristics of multistage microring resonators (MRRs) have been investigated while a soliton pulse is propagated. Effects of MRR radius, width, and gap between the MRR and the waveguide on the free spectral range (FSR) and the coupling coefficient have been studied. It has been shown that in the structure consisting of multistage MRRs, increasing the MRR radius and width would decrease the FSR. It is also indicated that by increasing the gap the width coupling coefficient would be enhanced at first, and then it would be diminished. The goal of this research is to improve the functionality of multistage MRRs by decreasing the FSR and increasing the coupling coefficient for soliton-based communication systems. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)