Propagation and conversion of light waves in graded-index planar waveguides

The concept of zigzag propagation of light rays in a dielectric waveguide is used to show how to determine the coefficient of attenuation of light representing its escape from the waveguide and the coupling constant of interacting waves in a periodically corrugated waveguide. It is also shown that this concept makes it possible to provide a simple explanation of some of the observations made earlier in relation to integrated optics.