Electromagnetic wave propagation in a fiber zoned with a metal-dielectric ring

The process of lightwave propagation in dielectric fibers is of great interest. This problem has been considered in detail previously with a variety of analytical and numerical methods. In our opinion the next step in lightwave construction simulation is the construction of dielectric or metal-dielectric inhomogeneities situated inside structures (for example scratches and damage) or next to them. Round constructions are of special interest. Here we have simulated the influence of a metal-dielectric ring on a fiber as it is plotted.