PDL-Tolerant Real-time Polarization-Multiplexed QPSK Transmission with Digital Coherent Polarization Diversity Receiver

This paper presents the implementation of a real-time electronic polarization tracking algorithm which enables robust optical polarization-multiplexed synchronous quadrature phase shift keying transmission with DFB lasers. The achieved BER at a data rate of 2.8 Gbit/s is well below the FEC threshold.