Generation and Detection of 28 Gbaud Polarization Switched-QPSK in WDM Long-Haul Transmission Systems

We report on an experimental long-haul transmission of a 28 Gbaud PS-QPSK signal in WDM scenarios. This report presents, to the authors' knowledge, a novel implementation of an optical coherent receiver for the polarization-switched quadrature phase shift keying (PS-QPSK) modulation format, with minor variations on the standard coherent PDM-QPSK receiver. We compare the performance of PS-QPSK with that of PDM-QPSK, over a WDM system based on 100 Gb/s PDM-QPSK and standard single mode fiber (SSMF), and we demonstrate its interest for software-defined optical transceivers operating over dispersion managed and non-managed transmission links.