From lab demo to field trial: Real-time coherent 127 Gb/s PM-QPSK transmission

We review the generation, detection and long-haul transmission of single-wavelength coherent PM-QPSK systems. The technology attributes of the 100G coherent transponder is first described from a system's perspective. Lab results then follow from various fiber-channel degrading effects, including cascading of more than ten 50GHz ROADMs over 1500km transmission test-bed. We conclude with a recent field trial of upgrading an installed 10-Gb/s field system to 100-Gb/s using an FPGA-based real-time, single-carrier, coherent transponder prototype. Transmission over installed 1800km link was achieved with sufficient performance for error-free operation after FEC.