Low loss optical MMI-based splitter based on a semi-analytical modeling approach

Abstract

For the realization of optical waveguide components, needed for photonic integrated circuits, a promising approach to manufacturing is their embedding in thin glass sheets by thermal diffusion processes. In this work, a semi-analytical approach to modeling the concentration profile of geometrically large components of a thermal ion-exchange diffusion process is evaluated to reduce the computational requirements to an absolute minimum. Conventionally, the modeling of integrated waveguide components manufactured by diffusion processes is based on solving the diffusion equation numerically. This approach, however, is based on the approximation of the analytical solution of the one-dimensional diffusion equation and its abstraction for a higher dimensionality. After introducing some general constraints with respect to the utilization of multimode interference effects (MMI-effects), the application to the modeling of these waveguide components is validated. The introduced error is evaluated and the excess and insertion loss of the modeled MMI-based splitters are calculated.