Single parameter scalar variational analysis for single-mode fibers with smoothed-out and composite refractive index profiles: A comparative study

A number of single parameter variational approximations for single-mode graded-index fibers have been reported in the literature. One of these approximations was also proposed by us some time ago which describes the propagation characteristics of such fibers having power-law profile with a high degree of accuracy. Using these approximations we have computed the propagation constant and the normalized dispersion for single-mode fibers with smoothed-out and composite refractive index profiles which are of great current interest. We have shown that the single parameter approximation proposed by us earlier computes these propagation characteristics with a better degree of accuracy than all other single parameter approximations even for these special types of profiles.