Dissipative self-organization, coherence transition dynamics in a Mamyshev oscillator

We report on the self-organization and the coherence transition dynamics during the establishment of mode-locking in a Mamyshev Oscillator. The Mamyshev oscillator consists of two offset filters and gain fibers in a cascaded arrangement. Light experiences periodic gains and spectral losses along the cavity, which can induce Faraday Instability even in the normal dispersion regime. Our simulation results show that there are two operational regimes of Mamyshev Oscillator. In the self-pulsating regime, the wavelength separation of the two offset filters is relatively small and the gain is relatively large. Laser mode-locking can initiate spontaneously without the need for external seeds. However, in the seed-driven pulsating regime, the separation of the two filters is relatively large, the mode-locking cannot self-start without an external seed. The numerical results show that there exist two distinct coherence transition pathways during the buildup of mode-locking in this regime. One is the coherence annihilation pathway, in which the seed coherence is lost during the mode-locking process. The other is the coherence memory pathway, in which the seed coherence can be preserved. In the coherence memory regime, we demonstrated synthesized dissipative soliton molecules and all-optical bit storage. All experimental results show that the seed-phase coherence remains intact in the coherence memory regime. Conversely, the phase coherence undergoes complete degradation in the coherence annihilation regime.