Steady and oscillating multiple dissipative solitons in normal-dispersion mode-locked Yb-doped fiber laser.

Multiple dissipative solitons are numerically studied in the normal-cavity-dispersion Yb-doped fiber laser. Soliton pairs and triplets of different types are found in parameter domain where single soliton mode-locking is unstable. Similar scenario is found for soliton pair and triplet: an additional weak soliton supplements already existing solitons, then with increasing gain the solitons start oscillating and at higher gain the soliton complex becomes stable. Spectral profiles of the solitons dynamically change taking either parabolic-like or Pi-like or M-like shape similar to those described in the literature for individual dissipative soliton at different pump level.