Evaluation of key parameters of 400Gbps WDM system

With worldwide deployment of 100Gbps coherent DP-QPSK, beyond 100G optical communication technology, which is featured by high-order modulation, spectral compression, flex grid, and super-channel, has become one focus of industry. The new features of physical interface lead new challenge on the system performance test and evaluation. Based on the discussion of test results of two kinds of typical 400Gbps solutions, which are different in spectral efficiency and transmission distance, we proposed and investigated several novel and practical test schemes to evaluate the key parameters of 400Gbps WDM system, including OSNR evaluation in super-channel multiplexed scenario, flex-grid optical channel spectrum analysis, and EVM related parameters measurement with transmitter impairments.