Influence of Spectral Broadening on Nonlinearity Compensation in Ultra-Wideband Optical Fiber Communications

Optical fiber networks form the major part of the modern telecommunication infrastructure and are carrying over 95% of the Internet digital data. The increasing demand for higher data rates has promoted the development of higher-order modulation formats, denser wavelength multiplexing and more powerful signal processing. With the entire suppression of the chromatic dispersion, the polarization mode dispersion and the laser phase noise using digital signal processing, Kerr fiber nonlinearities become the main capacity barrier for optical communication systems, and digital back-propagation is generally applied to overcome such distortions. Kerr effects also result in the broadening of spectra of signals propagating in optical fibers, owing to intra- and inter-channel nonlinear interactions. This report shows that the spectral broadening effect is crucial for achieving an optimal performance of the digital back-propagation in wideband optical transmission systems.