Statistics of second-order PMD depolarization

The second-order polarization mode dispersion (PMD) components associated with depolarization of the principal states can cause significant system impairments. We discuss the probability densities of these components and find excellent agreement between extensive measurements, simulations, and theoretical predictions.

I. Introduction

As the bit rate in optical fiber transmission approaches 40 Gb/s per wavelength division multiplexed (WDM) channel and beyond, the understanding of polarization mode dispersion (PMD), its system impairments, and broad-band compensation become of increasing importance. Several studies of second-order PMD impairments [1] [2]–[7] are already available. They show that second-order impairments due to PMD depolarization can lead to significant penalties in parts of the spectrum where first-order PMD of the fiber is low [7]. It has also been observed that first-order PMD compensators can induce detrimental levels of depolarization. The statistical properties of several first- and second-order PMD components have already been derived, measured, and simulated [8] [9]–[11]. Here, we extend the earlier work to include two key PMD components associated with PMD depolarization [12]. Fig. 1.

Poincaré-sphere plot of for a fiber with 14.7-ps mean DGD. The open circles mark 0.1-nm intervals.