Design Of Si-substrate Integrated Optical Filter Based On Micro-ring Resonator

As the feature size of transistor keeps deceasing,the fabrication of large-scale integrated circuits is limited by the basic physical principles,such as quantum tunneling effect.Electrical methods such as reducing the transistor size and improving the working frequency for improving the speed of the information processing has encountered the bottleneck.Since silicon on insulator material(SOI,Silicon on Insulator)has high refractive index,strong ability to limit the C-band light,compatibility with CMOS(Complementary-MetalOxide-Semiconductor)technology and other advantages,it has become the ideal material for optoelectronic devices.In recent years,the rapid development of integrated optics based on SOI materials inherited the development and ideas of integrated circuits for decades,and utilizes CMOS technology to achieve compact optical devices.Meanwhile,the photonic devices based on the SOI material can be modulated conveniently due to the plasma dispersion effect and the thermo-optic effect of silicon material,which greatly enriched the device function and scope of application.Microring resonator(MRR),consisting of a closed ring waveguide and a straight waveguide,is an important component of integrated photonic devices based on SOI.Because of its advantages of mature technology,highly integration and the mixed integration between optics and electrics,it is often used to build a variety of integrated optical devices.Transmission characteristics and applications of MRR based on silicon were studied in this thesis.Starting from the basic theory,the characteristics of SOI material system,typical micro/nano optical waveguide structures and the basic theories of silicon based micro/nano waveguide(electromagnetic field theory,frequency domain coupled mode theory and time domain coupled mode theory),especially the bending coupling of silicon-based micro/nano optical waveguides,were sorted out and explored.The filtering,switching and time characteristics of Add-Drop MRR were analyzed by the scattering matrix model.The main work includes the following points:(1)The fabrication process,test platform and test methods and test steps of silicon-based micro/nano photonic devices were described.(2)The single-mode conditions of silicon-based micro/nano waveguide,the relationship between the radiation loss and the bending radius,and the influence of the coupling coefficient and the coupling face design on the output performance of the device were analyzed.(3)Finally,a set of Add-Drop type MRRs with different coupling gaps and the width of 400 nm,height of 220 nm and the slab's thickness of 90 nm has been designed,fabricated and tested.And the relationship between the coupling distance and the free spectral region,optical bandwidth and quality factor has been obtained.