Analysis On Effect Factors Of Light Velocity Control And Quality Factor Of Microring Resonators

Due to their abundant transmission characteristics, microring resonators have been widely used as optical filters, dispersion compensators, add-drop multiplexers, etc. Also they can be used in light velocity control and sensing. In controlling the group velocity of light pulses, loss in a microring resonator often induces pulse splitting in addition to wearing down the pulse energy, whereas a gain microring resonator with identical dispersion can usually keep the pulse shape and make the pulse delay greater. Based on the symmetry between the transmission properties of microring resonators with gain and with loss and linear system theory, we reveal the mechanism by which gain improves the group-velocity control behaviors of the microring resonators and illustrate the effects of effective phase shift and loss/gain on pulse splitting and delay. Quality factor is an important parameter of microring resonators. However, effects of the polarization modes on quality factor of microring resonator lack of systematic research. In this thesis, using Meep software based on finite-difference time-domain method, coupler transmission coefficient and ring bending loss in two-dimensional waveguide microring resonators are calculated under TE and TM modes respectively, the reasons of different quality factors for different polarization modes and some relative relations are demonstrated.