The statistics of polarization-dependent loss in optical communication systems

In this letter, we study the statistics of polarization-dependent loss (PDL) in optical systems and evaluate its evolution with system length. We show rigorously that within the range of conceivable parameters in optical links, the distribution of PDL is Maxwellian when it is expressed in decibels. The accumulation of the mean-square PDL with system length stays linear in most systems, but may assume an exponential growth in very long systems with large PDL. The analytical results are compared with numerical simulations and an excellent agreement is observed.