Uniformly perturbed fibers

Perturbation solution for isolated fibers 18-2 Polarization of the perturbed fields 18-3 Uniform changes in profile... 

Another example of a three-region fiber is illustrated in Fig. 18-l(b). A thin concentric ring of width 6p and uniform refractive index n is introduced at the interface of the unperturbed fiber. Hence = n - in this region, and the perturbed propagation constant follows from Eq. (18-7) as... 

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