The Electrodes Research Of Organic Poiymer Electro-optic Modulator

Electro-optic modulator is a core device of optical fiber communication system,It allows the fiber to leverage the advantages of wide band.Organic polymer electro-optic modulators easier to achieve high bandwidth modulation,so in recent years, it has become the focus of research at home and abroad.And the electrode structure is an important factor in determining the characteristics of the electro-optic modulator.This thesis focuses on the design and simulation of organic polymer electro-optic modulator electrode system.Firstly,a suitable polymeric material was selected, the ridge type optical waveguide was designed to calculate the effective refractive index of the optical waveguide using the effective index method,effective index for impedance matching condition is very important in the electrode system design.Relevant parameters of the modulator was analyzed, half-wave voltage and 3dB bandwidth are important parameters associated with the electrode system.The two types of traveling-wave electrodes of organic polymer electro-optic modulators were concerned,microstrip line and coplanar waveguide electrode electrode.The basic principles,the relevant parameter and the electrode structures for organic polymer electro-optic modulator were analyzed.The advantages and disadvantages of both electrode system were compared.Then using HFSS,organic polymer electro-optic modulator electrode system was simulated and designed.First, a coplanar waveguide electrode structure with a better 3dB bandwidth was designed and simulated.Using HFSS to simulate, analyze and compare the specific structural parameters of interaction region, interface zone and transition zone,then the optimum value for each parameter was determined,ultimately the specific size of the model.Modeling and simulation,final 3dB bandwidth of up to 50 GHz.In view of the advantages of microstrip line electrode system,a microstrip line transfer coplanar waveguide electrode system was designed.The S-parameter of two kinds of electrode were compared.The reasons for the differences was analyzed,try to optimize the electrode structure to solve the problem of discontinuity field.The best microstrip line to coplanar waveguide transition structure with gold band transition method that effective solution to the problem of discontinuity field was described and analyzed.The the final electrode structure was simulated,3dB bandwidth of 30 GHz.Compare to the previous electrode tructure,it has improved significantly, electrode structure was successfully optimized.