Multimode optical fibres are finding increasing application in buildings, aircraft, trains, etc, for short-range communications. However, if information about individual modes is required, then traditional modelling techniques such as modal analysis or ray tracing are either inadequate or infeasible.

The purpose of this Faraday Partnership project is to develop a sophisticated mathematical and computational model that describes propagation through multimode fibres and devices. The model will take into account excitation, radiation, imperfections, tapering, coupling and scattering that occur in practical fibres and devices, and will enable accurate comparison to be made with experimental measurements. The large number of modes will be handled by moving to a continuum limit, which leads to differential equations of diffusion type.