A modified coupled-mode analysis for asymmetric coupled waveguides

Abstract

We present a modified coupled-mode formulation for an asymmetric two-waveguide coupler in which the trial field is expressed as a linear combination of the fundamental modes of the individual waveguides, with an additional phase-variation term determined from the orthogonality of the normal modes. The method provides more accurate solutions than the conventional theory, and the results satisfy power conservation. © 1996 John Wiley & Sons, Inc.