Limitations imposed by polarization-dependent gain and loss on all-optical ultralong communication systems

The performance degradation of an all-optical ultralong system due to polarization dependent loss and polarization dependent gain is analytically analyzed. In particular, both the mean and the standard deviation of the performance are calculated. The analytical predictions are compared against a computer simulator, which includes the effects of nonlinearity and polarization mode dispersion. The result show that polarization dependent gain is the major source of degradation for the mean performance, while both polarization dependent loss and gain affect the standard deviation from the mean performance. Finally, the performance improvement due to polarization scrambling is evaluated