Long-range Coulomb-like mode interaction in a coaxial waveguide filled with Faraday material

Nonlinear mode coupling in a coaxial waveguide filled with Faraday material has been considered. The picture of mode interaction is shown to resemble Coulomb interaction of charges: higher modes with nonzero angular momentum interact like effective charges via exchange of zero angular momentum quanta of the fundamental mode. Thus, at large distances this interaction becomes the dominant mechanism of mode coupling. The developed model may be used in designing coaxial photonic crystal fibers with strong tailored mode interaction.