The design and analysis of a racetrack resonator based on a multimode interference (MMI) coupler are presented in this paper. In order to describe the characteristics of an MMI coupler, a matrix description of the MMI coupler, which takes into account the effect of higher order modes in the structure, is developed. A design approach that is based on this matrix description is proposed. The usefulness of this design method is illustrated by means of an example based on Silicon on Insulator (SOI) technology
