IN-FIELD COMPARISON AMONG POLARIZATION-MODE-DISPERSION MEASUREMENT TECHNIQUES

We report polarization mode dispersion measurements on a 168 km long u ndersea optical cable, performed with two techniques. From experimenta l results, statistical behavior of polarization parameters and their t ime fluctuations have been extracted. An average differential group de lay of about 13 ps shows that dispersion-shifted fibers can be affecte d by a polarization dispersion significantly larger than standard step -index fibers. The correlation length of the polarization-coupling per turbation in the tested fibers is not negligible with respect to the l ink length.