有限元分析法在SOI基微环谐振器设计中的应用

利用有限元法(FEM)分析了大横截面SOI(Silicon-on-insulator)脊型波导的本征模式分布,确定了脊型波导的单模条件。在保证单模传输的情况下,模拟了SOI微环谐振器中波导耦合器的耦合长度、功率耦合系数与波导尺寸和间距的关系。模拟结果表明:对于W=1μm,H=2μm的SOI脊型波导耦合器,耦合长度LC随波导间距d的增加而增大,功率耦合系数随之减小。在波导间距d0.8μm的情况下,耦合长度LC随着归一化脊高r的增加而增大,当d0.8μm时,耦合长度LC随r的增加而减小。模拟结果为SOI微环谐振器的设计和应用提供了理论依据。

Finite Element Analysis on SOI-based Microring Resonator Design

The single mode condition for a rib waveguide with large cross section based on silicon-on-insulator (SOI) is determined through the eigenmode analysis by finite element method (FEM). The mathematic model of waveguide coupler based SOI rib waveguide is established, and the relationships among coupling length, power coupling coefficient, waveguide dimension and separation are calculated and analyzed under the condition of single mode operation. The simulation results indicate that coupling length Lc increases and power coupling coefficient decreases with increasing the waveguide separation for a SOI rib waveguide with W=1 μm and H=2 μm. Furthermore, Coupling length Lc increases with increasing the normalized height (r) of rib waveguide when d＜0.8 μm, but it decreases with increasing r under the condition of d＞0.8 μm. The simulation results provide a guideline for the design and application of SOI-based microring resonator.