Distributed loss and mode coupling and their effect on time-dependent propagation in multimode fibers

A first-order solution to the transport equation for the total power propagating in each degenerate mode group of a multimode fiber is used to describe pulse propagation in multimode fibers. The basic transport equation is supplemented by models for Rayleigh-scattering-induced losses, mode coupling, and the modal group velocity function. Each of these models can be specified for a particular fiber from a standard set of near-field measurements and then incorporated into pulse propagation simulations, which closely matched the measured pulse response of test fibers.