Study of PMD and PDL Equalization Via a Nonunitary FIR Lattice Filter

We study a novel configuration and synthesis algorithm for equalization of polarization-mode dispersion (PMD) alone and combined with polarization-dependent loss (PDL) using a nonunitary optical lattice filter (NU-OLF). The NU-OLF is a generalization of a previously studied unitary lattice filter (U-OLF) for PMD equalization. Comparison of the improvement in the noise loaded PMD/PDL-induced eye closure, for typical optical signal-to-noise ratio values, shows that a NU-OLF is always superior to a U-OLF of the same order and it offers a significant advantage over a U-OLF with the same number of degrees of freedom in the equalization of PMD in the presence of PDL.