Phase Evolution of Peregrine-Like Solitons in Nonlinear Fiber Optics

Optical fiber systems are well-known to provide convenient platforms in which one may investigate a large variety of fascinating fundamental nonlinear coherent structures such as solitons or self-similar patterns. Interestingly, one of the major conclusions of the studies dealing with extreme-value fluctuations is that the temporal and spectral characteristics of localization processes can be well described in terms of solitons over finite background and in particular in terms of Peregrine soliton (PS) [1]. Whereas the longitudinal evolution of the temporal and spectral intensity of the PS have been characterized in detail [2], much less attention has been experimentally devoted to the evolution of its phase properties. We report here a study that complements the analysis of the nonlinear dynamics of this coherent structure: by exploring the longitudinal evolution of the temporal phase profile and the phase difference Δϕ between the central part of the pulse and the continuous background, we experimentally confirm some important features of the PS [3].