Modes of a Slot Waveguide Structure
应用文章
This application note demonstrates the use of FemSIM to analyze the modes of a slot waveguide structure using the finite element method (FEM). The structure consists of two identical buried silicon channels in a uniform silicon dioxide (SiO2) background, separated by a small distance. The large discontinuity at the waveguide boundaries and the close spacing lead to tightly confined modes.
The fundamental Transverse Electric (TE) mode is first computed using a coarse grid, and a convergence study is performed by refining the mesh size along the X direction. As the grid is refined, the effective index results begin to converge.
To improve simulation efficiency, the example applies advanced non-uniform grid features, which allow finer resolution at material interfaces without increasing resolution in the entire domain. This results in higher resolution fields near the core regions with minimal impact on simulation time. The mode profile obtained matches published results, confirming the accuracy and effectiveness of the approach.