Perturbation model for computing optical fiber birefringence from a two-dimensional refractive-index profile

A vector perturbation model for computing optical fiber birefringence for an arbitrary two-dimensional index profile is developed. The vector wave equation is solved to yield the unperturbed vector f ields for an azimuthally symmetric refractive index. These f ields are used as the basis for the degenerate perturbation analysis. Unlike with the scalar perturbation theory, only f irst-order perturbation analysis suff ices for the computation of birefringence. Computed birefringence for various perturbations are reported.