Nonlinearities Estimation in Optical Fiber Communication: Current Progress, Challenges and Perspectives

This review paper gives a comprehensive review of nonlinearities and recent advances in nonlinearities estimation in optical fiber transmission systems. The most frequent irregularities in optical communication systems are Four-Wave Mixing (FWM), Self-Phase Modulation (SPM), and Cross-Phase Modulation (XPM). These nonlinearities have a significant impact on optical performance (i.e., bit error rate, optical signal-to-noise-ratio, Q-factor) and capacity by limiting the data rates. Accurately estimating these nonlinearities is crucial for designing robust, high-capacity fiber optic networks. This paper discusses nonlinearities estimation using experimental methods and highlights recent advances in nonlinearities estimation using machine and deep learning-based approaches. Traditional experimental methods for estimating nonlinearity in optical fiber communication are limited by their complexity, high sensitivity requirements, high costs, accuracy issues. and limited real-world applicability. The paper concludes with an outlook on future research directions in nonlinearities estimation to enable the development of next-generation optical communication systems.