HELICAL SURFACE WAVES ON A DIELECTRIC ROD

The conventional formulation of the electromagnetic field solution for a cylindrical dielectric rod is re-interpreted in a novel fashion in order to show the presence of surface waves which propagate over the rod's surface along helical paths. The solutions of the characteristic equation of the rod are interpreted in terms of the resonances at which these helical surface waves azimuthally match phases after each circumnavigation of the rod, effectively forming resonating standing waves around the rod. This interpretation permits us to obtain the pitch angle of the helix, and the dispersion curves (phase velocity as a function of frequency) of the helical surface waves.