On the sustainment of optical power in twisted clad dielectric cylindrical fibers

The paper presents an analytical investigation of twisted clad dielectric optical fiber with the emphasis on the propagation of power through the guide. The fiber structure assumes twists in the form of loading of conducting sheath helical windings with a particular value of pitch at the core–clad interface. It is assumed that the turns of right-handed helical windings are continuous in nature, but still insulated from each other. The dispersion relation is deduced for the structure followed by the evaluation of the propagation of power (in terms of power confinement factor) under different values of helix pitch angle. It has been found that the pitch plays determining role to control power confinement in the guide as the amount of power in the core section is found to be the maximum corresponding to 0° pitch and goes on decreasing with the increase in its value. It is presumed that such characteristics of the guide would be useful to device varieties of optical components wherein the need of tuning optical power propagation remains vital.