WDM Performance and PMD Tolerance of a Coherent 40-Gbit/s Dual-Polarization QPSK Transceiver

We report the measured wavelength-division-multiplexing (WDM) performance and polarization-mode dispersion (PMD) tolerance of a coherent 40-Gbit/s dual-polarization quadrature phase shift keying (DP-QPSK) transceiver at 50-GHz minimum channel spacing in a 40-channel 40-span test bed comprised of 3200 km of uncompensated G.652 fiber. We also evaluate the impact of polarization-dependent loss (PDL) on system performance and present the measured tolerance to frequency misalignment between the transmitter and a multiplexer/demultiplexer filter pair.