A note on the evaluation of modal coupling coefficients at planar waveguide junctions

The explicit expressions of modal coupling coefficients at planar waveguide junctions are discussed. The coupling coefficients are expressed in terms of projections of the modes on the modal spectrum of a fictitious rectangular waveguide located at the junction plane. The proposed formulation results in an efficient implementation of the modal based analysis of waveguide junctions. Copyright © 2005 John Wiley & Sons, Ltd.