Modelling and optimising planar waveguide devices

The availability of powerful optical waveguide modelling software packages has enabled designers to analyse quite complicated waveguide structures. However, there still remains the challenge of synthesing waveguide designs without carrying out an inordinate amount of trial and error computation. General numerical optimization algorithms have proven to be of limited value and they can suggest structures that are difficult to fabricate. The purpose of this paper is to highlight the advantages of using semi-analytical results in a more logical approach to the synthesis of planar waveguide devices. The proposed approach is illustrated by optimizing the performance of a multimode interference power splitter.