Study Of The Production Process Of The Simulation And Design Of The Optical Coupler And Waveguide Devices

In two and half years' graduate study,I focused my efforts on simulation and design for optical communication devices and study of fabrication technologies for optical waveguide devices. 1 summarized my main research results and wrote this thesis.The first part of this thesis is for simulation and design of planar waveguide optical couplers. Optical couplers play fundamental roles in passive optical distribution networks and complex photonics integrated circuits. In this thesis,optical couplers consisting of multimode interference (MM!) coupler,Y branch,directional coupler(DC) and Mach Zehnder interferometer(MZI) were analyzed and simulated. First,I made and improved some Beam Propagation Method (BPM) programs,consisting of 2D(EIM-BPM) and 3D BPM,with transparent boundary condition(TBC) and perfectly matched layer(PML) boundary condition respectively. Applying an exact modal propagation analysis method and self-imaging theory,I analyzed the principle of MMI coupler. Then,the self-imaging effect in graded-index waveguide has been analyzed and simulated using three-dimensional BPM. Considering normal technology error,a low loss Y-branch structure (symmetric or asymmetric) with a multimode waveguide transition section is introduced and designed. A wide range of the branching ratio can also be achieved for the asymmetric case. Using supermode theory,I compared the design results of directional coupler by means of 2D mode and 3D mode and designed 3dB directional coupler using 3D BPM and couple mode theory. In order to design wavelength insensitive power splitter based on SOI,the wavelength characteristic of Mach-Zehnder interferometer were investigated by means of BPM and FDM (finite-difference method). Then the parameters of Mach-Zehnder interferometer were optimum designed using genetic algorithm. Besides,genetic algorithm is also used to optimize the upper tier parameters of MZI based silica-on-silicon to attain a flat spectral response.The second part of this thesis is for the study of fabrication technologies of optical waveguide devices. The technologies I explored consist of photolithography technology,Lift-off lithography process,technology of growing silicon dioxide films using Sol-Gel coating technique,and fabrication of Na+-K+ ion-exchanged glass waveguide. In this thesis,the experiment principles were investigated and the experimental results were given and discussed...