A review of advancements in DP-QPSK WDM systems.

Dual polarization quadrature phase-shifting keying (DP-QPSK) wavelength division multiplexing (WDM) systems are currently acting as the backbone of long-haul optical networks. It has provided a cost-effective solution for network up-gradation due to its backward compatibility on legacy infrastructure of standard single-mode fiber. Encoding of two bits per symbol per polarization, low BER over long haul transmission reach, and simple digital equalization techniques are the main features of 100G DP-QPSK technology. A large amount of voice, video, and high-speed data services are being provided by DP-QPSK WDM-based optical networks. This paper reviews the progress happened in the DP-QPSK WDM system since its introduction. The work is focused on reviewing important incorporations researched and developed related to the transmitter and digital coherent receiver. [ABSTRACT FROM AUTHOR]