Polarization-dependent loss as a waveform-distorting mechanism and its effect on fiber-optic systems

This paper presents a study on the effect of polarization-dependent loss (PDL) as a waveform-distorting mechanism in the presence of polarization-mode dispersion (PMD) and assesses its significance in fiber-optic communications links. A simple model is introduced that illustrates the joint effect of PDL and PMD on the transmitted waveforms within the first-order approximation in the transmitted bandwidth, and the nature of possible distortions is discussed. This paper analyzes the statistics of the PMD and PDL vectors and derives explicit formulas for their mean-square magnitudes. These formulas are used to show that, in systems with realistic parameters, the waveform-distorting effects of PDL are of very limited significance.