Generalized analysis of the polarization evolution in high-birefringence fibers

A generalized input polarization analysis of the relative state of polarization between two signals in high-birefringence fibers is presented. The degree of co-polarization is calculated as a function of the polarization orientation and ellipticity of the two input signals, for two different input polarization schemes. It is shown that for small fiber lengths or narrow wavelength separation, launching the two signals with orthogonal polarizations can present a higher degree of co-polarization along the propagation. For higher ellipticity values the dependence of the degree of co-polarization on the angle between the major axis of the ellipsis and the principal axes vanishes.