Impact of Loss and Gain on the Nonlinear Spectrum of Dense Optical Soliton Gases

Soliton gases (SGs) are large random ensembles of interacting solitons [1]. While they can, in principle, exist in various physical systems, they have only recently been observed and precisely characterized in hydrodynamics [2], [3], and in optics [4]. Due to the large number of solitons involved, their behavior requires a statistical description, which is provided by a kinetic theory [3], [5]. However, this theory has been developed for ideal, non-dissipative systems, where the soliton distribution within the gas remains unchanged during system evolution. Here, we present an optical fiber experiment where weak dissipation breaks this ideal situation, leading to remarkable changes in the distribution of the solitons' characteristics.