Collision dynamics of co-propagating solitons in mode-locked fibre laser with net-anomalous dispersion

Abstract

Nowadays, real-time measurements of complex dynamics of ultrashort structures in dissipative nonlinear systems have attracted a lot of interest. In this work, we present experimentally obtained real-time dynamics of two closely-separated solitons in a mode-locked erbium fibre laser. Both solitons experienced strong temporal vibrations due to mutual attractive and repulsive forces, alongside with oscillation in their energies. We experimentally demonstrate the influence of the dispersive waves (DWs) on the dynamics of the soliton complex. Eventually, the pulses experienced a collision dynamics that resulted in the formation of a single soliton at a shifted central wavelength with highly energetic Kelly sidebands and increased background radiation. Our experimentally obtained results prove the theoretical works on soliton interaction and enrich the knowledge on the complexities of ultrashort coherent features and their behaviour in nonlinear systems.