Real-time observation of dissipative multi-soliton complexes in a net-normal dispersion fiber laser

Abstract Recent progress in real-time measurement technology makes it possible to spectrally characterize multi-soliton complexes. Here, we report on real-time observation to the multi-pulse structures in a net-normal dispersion mode-locked fiber laser. With careful adjustment of cavity parameters, several kinds of multi-soliton complexes, such as the coexistence of soliton singlet and soliton molecule, as well as the coexistence of different types of soliton molecules, are realized in the experiment. Real-time spectral information of each pulse under multi-soliton states can be well resolved with the dispersive Fourier transformation technique, which is markedly different from the results measured by conventional measurement instruments. Note that this is the first reported the simultaneous generation of different types of soliton molecules in a fiber laser to our best knowledge. The findings help to understand the complicated dynamics of the coexisting pattern between different kinds of dissipative solitons.