Abstract
Analytical evaluations of the minorx-component of a LPO1 mode polarized alongy-axis in strongly birefringent optical fibers are proposed, for weakly guiding step-index fibers. In the assumption where the\bar{\bar{\epsilon}}-tensor is everywhere diagonalized inx-y-zaxes, it is shown that the anisotropy has little effect on the minor component and that the polarization ratio (Expower/Eypower) remains within a few decibels from its value in an isotropic fiber. A considerably larger change can be predicted from a more realistic analysis of real birefringent fibers, taking into account the nonuniformity of the stress which produces the birefringence; this nonuniformity makes off-diagonal coordinates-dependent terms to appear in the\bar{\bar{\epsilon}}-tensor. A recent experimental report can thus be explained.