A phenomenological approach to polarization dispersion in long single mode fibers.

We describe a phenomenological approach to polarization dispersion in long single mode fibers that is based on the existence of principal states of polarization. These are two orthogonal input states of polarization that have corresponding output states that are orthogonal and exhibit zero dispersion in their state of polarization to first order. These states could prove useful in describing and characterizing polarization dispersion in fibers of arbitrary length and configuration even in the presence of strong polarization mode coupling.