Accurate closed-form model for nonlinear fiber propagation supporting both high and near-zero dispersion regimes

Abstract

Legacy fibers with near-zero and even zero-dispersion bands are being re-purposed worldwide to host modern coherent systems, in the quest to exploit all possible deployed cables. Non-linearity modeling for these legacy fibers has not been investigated in depth and no fast closed-form models are available which are capable of dealing with them. In this work, we first investigate the accuracy of the EGN model for the prediction of the impact of fiber nonlinearity on optical coherent transmission systems at zero or near-zero dispersion. We find the EGN model to be accurate in predicting system performance. We then derive a closed-form EGN-model approximation capable of handling any combination of high, low and near-zero or zero dispersion fibers, which we thoroughly test over 9,000 randomized system scenarios. The good accuracy and real-time computation speed of such a closed-form model potentially makes it a highly flexible tool for supporting physical-layer-aware management of optical networks, capable of dealing with all types of fiber, including legacy ones.