Modal Analysis for Single-Mode Waveguides of Silicon on Sapphire (SOS) at Infrared Region Using Finite Element Method (FEM)

One of the recommended platforms for waveguide generation in the infrared region is silicon-on-sapphire (SOS). This paper proposes a modal of the optical waveguide of silicon on a sapphire from λ = 2 − 5 𝜇𝑚 , using FEM (finite-element method) solver simulation performed by FDTD [finite-different-time-domain]. The waveguide is directly based on the refractive index difference between the wave's guideline regions and surrounding media (cladding). The use of FEM to analyze a single waveguide mode of SOS at a certain size within multiple wavelengths is a unique aspect of this research. In addition, this project's objective is to discover how the waveguide size (dimension) impacts single-mode waveguides in the infrared region. The investigation includes single-mode polarization with both transverse-magnetic TM 0 and transverse-electric TE 0 polarization. The waveguide is reliant on the effective index of different mediums, and sizes of substances, they have a significant role in generating waveguide with minimum loss (minimum dispersion). The study's most crucial finding is that single-mode can be achieved in silicon with widths ranging from 0.4 − 4.5 𝜇𝑚 and height ranging from 0.4 − 0.7 𝜇𝑚 as well as analysis the characteristics of mode polarization and explain those parameters have a massive role in the waveguide like effective index, sizes of structure and wavelength. In keeping with our modal analysis, we also state the mode's characterization and direct some factors' influence on the waveguide.