Coupled-mode formulation of two-parallel circular dielectric waveguides using singular perturbation technique

The author presents a self-consistent coupled-mode formulation of vectorial form for the two-parallel circular dielectric waveguides, using a singular perturbation technique. In this approach, the original uncoupled wave equations for the coupled waveguides are decomposed into an equivalent system of coupled wave equations. The coupled wave equations are solved iteratively using the multiple-space scales so as to satisfy the Maxwell equations and the boundary conditions of the coupled waveguides. The coupled-mode equations are obtained in analytically closed form, which is rigorous within the first-order perturbation.>