Analysis of Coupling Effect in Coupled SOI Rib Waveguide for Different Polarization Mode

Abstract

Parallel coupled Rib waveguide based on silicon-on-insulator (SOI) has been explored to analyze the coupling effect on different polarization mode using the simulation approach based on the finite element method and the semi-vector finite difference beam propagation method. The minimum coupling effect has been analyzed with respect to variation of geometry parameter and comparison of different polarization modes ($E_{11}^x$ and $E_{11}^y$) in parallel Rib waveguide. The coupling effect has been observed with respect to the variation in waveguide spacing (S) for some fixed value of ratio of slab height to total Rib height (i.e., r = h/H), such as 0.6, 0.7, and 0.8 under single mode propagation constraint at operating wavelength of 1.55 µm. However, the coupled Rib waveguide with r = 0.6 at the different waveguide spacing is most suitable for the minimum coupling effect and for the enhancing the data transmission capacity.