A modified zigzag-ray model of light propagation in a dielectric slab waveguide

A modified zigzag-ray model of light propagation, in which the Goos-Hänchen shift and the associated time delay are included, is used to examine the applicability of a conventional zigzag-ray model for the calculation of the impulse response of a multimode cladded optical fiber. As a model of the fiber, a symmetric slab waveguide is considered, and it is shown that there exists a considerable discrepancy in the durations of the impulse responses calculated from the modified and conventional ray models, even for a very large value of the film thickness to wavelength ratio.