Model Analysis of Ridge and Rib Types of Silicon Waveguides With Void Compositions

Detailed numerical study on mode characteristics and light confinement properties of ridge and rib waveguides with vertical, horizontal, and cross types of void configurations is presented. The study starts from the mode analysis for rectangular ridge and rib waveguides. Then, the analysis is extended to semicircular ridge and rib waveguides with and without slots. The percentages of the electric and magnetic field components and light confinement capabilities are compared. We observe that polarization type of the mode and strong field confinement in the low refractive index medium can be achieved by the incorporation of void structures into the regular optical waveguide.