Influence of width of launch beam distribution on equilibrium mode distribution in W-type glass optical fibers

Power flow equation is used to calculate spatial transients and equilibrium mode distribution in W-type glass optical fibers (doubly clad fibers with three layers). A numerical solution has been obtained by the explicit finite difference method. For the first time, we have shown how the coupling length for achieving the equilibrium mode distribution in W-type glass optical fibers varies with the depth and width of the intermediate layer and coupling strength for different widths of launch beam distribution. Such characterization of these fibers is consistent with their manifested effectiveness in reducing modal dispersion and bending loss.

► Equilibrium mode distribution (EMD) is calculated in W-type optical fibers.
► Power flow equation has been solved by the explicit finite difference method.
► EMD varies with fiber structural parameters and width of launch beam distribution.