Revealing the Ultrafast Soliton Dynamics in an All-Fiber Self-Starting Er Mamyshev Oscillator

The fiber Mamyshev oscillator (MO), as a high-performance fiber oscillator that delivers high-peak-power pulse, has been intensively investigated. However, one major difficulty in the MO is the self-starting capability, and rare efforts have been dedicated to unveil the real-time soliton dynamics of the all-fiber self-starting MO. Herein, we construct an all-fiber self-starting erbium-doped Mamyshev oscillator, and by utilizing time-stretching dispersive Fourier-transform (TS-DFT) technique, we reveal the distinct dynamical diversity of pulsating solitons. Firstly, the self-starting mode-locking process is studied, in which the evolution from noise to mode-locking state is found. Subsequently, a variety of soliton pulsation states are studied, such as invisible soliton pulsation, and even a chaotic pulsation state. More interestingly, we further investigate invisible soliton molecule pulsation and soliton explosion of soliton molecule. It is found that the occurrence of invisible pulsation is mainly due to self-phase modulation (SPM) effect which exists in nonlinear optical fiber systems. To the best of our knowledge, this is the first observation of invisible soliton molecule pulsation in an all-fiber erbium-doped MO. In addition, optical turbulence and harmonic mode-locking are also observed. We believe our work is of great significance to enrich the study of nonlinear physics in dissipative systems. These experimental observations will enrich the understanding of pulse dynamics in the fiber MO, which will have prospective applications including laser micromachining and frequency comb ranging fields.