Optimization Design And Characteristic Analysis For Polymer Micro-ring Resonant Wavelength Multiplexet

Micro-ring resonators can be used as the basic elements of the optoelectronicdevices such as filters, multiplexers, modulators, lasers and others. The kind ofcomponents have promising application due to their simple structure, easierfabrication and compactness. At present, polymers used in optical waveguides arepromising materials for fabricating photoelectric integrated devices because oftheir excellent photoelectric characteristics, lower cost and simpler fabrication. The purpose of research in this thesis is: First, the working principle of Micro-ring Resonant Filters (MRRF) andMicro-ring Resonant Wavelength Multiplexers (MRRWM) is expatiatedtheoretically in detail. Second, the structural designs of MRRF and MRRWM withpolymers based on silicon are optimized, on the basis of which the relative opticalcharacteristics are discussed and analyzed in detail by the results of numericalsimulation; hence all the relevant design data and necessary theoretical basis forthe fabrication of vertically coupled structural 1×8 channel polymer MRRWM inthe laboratory. The paper consists of two parts. 1. The theoretical analysis of the design principle of MRR. On the base of introducing the theory of mode describing transmissioncharacteristics of the guided wave, the coupling of bent rectangular dielectricoptical waveguides is analyzed in detail in terms of the coupled mode theory indielectric optical waveguides, and the amplitude coupling equation of bentwaveguides is derived using the method of transmission matrix. Those provide thesufficient theoretical basis for describing the design principle of MRR. Then themicroring resonant equation is derived from the transfer function of light intensityof MRR with a single ring using the coupled mode equations, which is the direct iAbstracttheoretical basis for the operating principle of MRR. By means of describing thedesigning principle of MRR, a conclusion is arrived that the microring resonantorder m is an key parameter which determines the others such as the microringradius R, the free spectrum range FSR and others. 2. Optimization design and characteristics analysis of MRRWM. In order to learn the transmission characteristics of MRR, parametersoptimization of side-coupled MRRF with a single ring is carried out, and itstransmission characteristics is numerically simulated. The results show that thefiltering properties of MRRF is affected by different values of parameters. Forexample, microring resonant order m determines the values of the microringradius R and the free spectrum range FSR; the thickness of the coupling layer dbetween microring waveguides and channel waveguides determines the values ofthe amplitude coupling ratio ? and the amplitude transmission ratio t, hence thecoupling efficiency at the working wavelength and the 3dB bandwidth of theresonant peak. In contrast with side-coupled MRRF with a single ring, the specificity ofstructure and function of MRRWM determines the complexity of its structuraldesign. The basic demultiplexing unit is a MRRF with a single ring verticallycoupled, which is advantageous to select materials for waveguides and control thethickness of the coupling layer. On the other hand, vertically coupling willincrease difficulties to structural design. In particular, the optimized structure ofMRRWM must be designed more carefully because of its fundamental functionsof demultiplexing/multiplexing. In the part of optimization design of MRRWM, first the selection of therefractive indices of claddings and cores of microrings and channels is carried out,then the dimension of optical waveguides is optimized in according with specificdesires of single mode propagation, and the effective refractive indices of thefundamental modes E ' x, E x , E ' y and E y of microrings and channels 00 00 00 00waveguides are equ...