The devil's staircase and its intracavity pulse dynamics in an inverse-configuration dispersion-managed soliton laser

The devil's staircase is a ubiquitous fractal phenomenon in nonlinear systems, and was recently extensively studied in dispersion-managed mode-locked fiber lasers with near-zero dispersion. Generally, dispersion management is realized by employing a piece of normal-dispersion gain fiber and a segment of anomalous-dispersion single-mode fiber. Thus, an amplifier similariton shaping mechanism naturally presents in the gain fiber, suggesting it is correlated to the generation of the devil's staircase. It is natural to ask whether the devil's staircase persist when the amplifier similariton shaping is absent. We address this question by numerically investigating an inverse-configuration dispersion-managed soliton laser. In this case, dispersion sign of the gain fiber and the passive fiber is reversed, thus the amplifier similariton shaping no longer exists. Interestingly, the devil's staircase is still observed in the laser. Further investigation reveals that passive similariton is correlated to the fractal dynamics. This work establishes a connection between the devil's staircase and passive similariton, providing new insights into the studies of fractal soliton dynamics and potentially inspiring novel laser designs.