Polarization and topological mode dispersion of optical vortices in circular optical fibers

In this paper we investigated a problem of intermode dispersion within a group of optical vortices with an azimuthal number greater than or equal to 1 in circular optical fibers. It was established that, while there is no dispersion between optical vortices with topological charge $\pm 1$, both standard polarization mode dispersion and a new-form topological mode dispersion occurred between optical vortices with the topological charge greater than 1. The dependence of the dispersion of optical vortices on the wavelength for the gradient and step-index fibers with variable parameters was numerically obtained and analyzed. A feasibility of zero mode dispersion in step-index fibers was established.