The dynamics of scalar pure quartic soliton evolution in the Mamyshev oscillator

The Mamyshev oscillator (MO) emerges as a breakthrough in mode-locked fiber lasers, enabling ultrashort pulse generation. The MO-enabled mode-locked fiber lasers can address nonlinearity-induced instabilities, ensuring stable, highpeak-power pulses. The MO also unlocks the potential for advancing ultrafast optics research and applications. Recent innovations integrate higher-order dispersion (HOD) management, particularly fourth-order dispersion (FOD), to refine the performance of the MO. In this manuscript, we numerically investigate quartic soliton generation and evolution in an MO with FOD management, optimizing pulse duration and peak power. Our numerical study explores stable pulse formation through the interplay of FOD control, nonlinearity, gain, and loss. In particular, the spectral and temporal profiles of the pulses remain unaffected even after 500 round trips, demonstrating their robustness. Also, we reveal that dispersion management, in particular FOD dispersion management, causes significant pulse broadening in positive FOD, followed by rapid compression in negative FOD, resulting in a sharp increase in peak power. These results confirm the feasibility of FOD-managed pure quartic solitons in MOs for ultrashort pulse generation. Furthermore, we observe that slight variations in small-signal gain significantly influence the temporal and spectral characteristics of the pulses. The rich dynamics of FOD-managed pure quartic solitons in MOs provide deeper insights into nonlinear pulse evolution and offer valuable guidance for developing high-power fiber lasers.