Field perturbations due to strong coupling and modal confinement in SOI arrayed waveguides

We present a method of rescaling the basis set used in coupled mode theory for constructing the mode profiles of silicon-on-insulator strongly coupled arrayed waveguides. We show that due to strong coupling the decay constants of the supermodes fanout, and can become spatially varying due to the vertical confinement of the mode. Further, we show that in strongly coupled arrayed waveguides the field peaks are no longer centered within their dielectric boundaries.