Design Of Optical Filter Based On Microring Resonator

With the arrival of the global information era，communication technology with hugecapacity, high rate of network is the inevitable trend of the development of communicationtechnology. The integrated optical device has the advantages of miniaturization,modularization, integrated, become the future development trend of optical communicationdevices. Micro-ring resonator has the advantages of multiple functions, small size, goodwavelength selectivity, has been widely applied in the field of optical communication.In the thesis, the development situation and the basic structure of the micro-ringresonator were summarized firstly, and performance parameters as well as several commonstructures of micro-ring resonators were introduced.Based on mode coupling theory, the power transfer function of micro-ring resonatorwas researched by using the transfer matrix method, and then the coupling efficiencybetween two waveguides was discussed. The coupling efficiency between annularwaveguide and direct waveguide was studied as a special case of coupling between twocurved waveguides; key factors which influence on the coupling efficiency were simulated.Two simulation methods for micro-ring resonator (FDTD and BPM) were introduced.The simulation steps of these methods as well as boundary condition of BPM method wereanalyzed. And the comparison of the FDTD and BPM for micro-ring resonator was givenhere.According to the previous analysis, the structure parameters which influence theresponse were researched, such as the radius, the gaps between micro-ring and thickness ofwaveguide, as well as the difference index of refraction. The results show that the bendingradiation loss, quality factor (Q) and the free spectral range (FSR) are increased, while theradius of micro-ring is reduced. The amplitude coupling ratio k is reduced when the gapsbetween micro-ring and bus waveguides is increased. The width of waveguide relatively hasa smaller influence on the performance. The amplitude coupling ration k is also reducedwhile the difference index of refraction is increased.At last, the structure parameters were optimized with FDTD. The results show that, thefull bandwidth, FSR and the shape factor were improved after optimization.