Buildup dynamics of the soliton molecules in a self-starting Mamyshev oscillator

Since Mamyshev oscillator is difficult to start a mode-locked state, only a few rare efforts have been dedicated to unveiling the buildup dynamics of soliton molecules (SMs). Here, we focus on addressing this issue. It is revealed that there are two different SMs formation processes for two different self-starting modes. Specifically, for single pulses self-starting, the number of pulses inside SMs gradually increases one by one with pump power. While for multi-pulse self-starting, SMs are generated simultaneously and then disappear simultaneously. That is, a smaller SM containing a few pulses can be formed at small pump power. By simply increasing the pump power, these pulses within SMs disappear simultaneously. Continuing to increase the pump power will result in the formation of a larger SMs containing one more pulse than before, and so on. In addition, both SM formation modes exhibit bistability. These findings enhance the understanding of nonlinear dynamics.