Development of the EM coupling in laminated multilayered 3D optical waveguides

The theoretical investigation of waveguides having non-Uniform cross-section is an attractive and challenging problem which arises serious interest. In this paper, we develop the analysis of laminated multilavered 3D-waveguide, by the three following steps: (i) Coupled Mode theory (CM) is generalized and compared with Local Mode theory (LM). The latter is a rigorous technique which accounts for propagation, diffraction and coupling in it non-uniform environment. (ii) The two approaches are then applied to the problem of polarization Coupling in a laminated rib-waveguide S-i : H-SiO2. For moderate optical axis slant (low hybridization) and fixed layer thickness the two theories yields similar results, while LM becomes mandatory when hybridization is important. (iii) Finally, we validate and complete the EM analysis by using the finite element method (FEM) for the 3D modelling of the structure