IMPROVED COUPLED-MODE THEORY OF PARALLEL OPTICAL WAVEGUIDES

Abstract

In this paper the transverse coupling between coupled parallel two dielectric slab waveguides (slab-slab) is
analyzed for the first time –to the author's knowledge by Improved Coupled- Mode Theory (ICMT). The
coupling is established via the evanescent part of the modal field propagating in one waveguide which
penetrates the other waveguide. The overlap integrals, coupling coefficients, asynchronism factor, output
powers and coupling lengths are evaluated numerically by ICMT, where the results obtained reveal an accuracy
improvement over that obtained by the conventional coupled mode theory (CMT).