Yang, Song; Zhu, Zhiwei; He, Chaojian; Shi, Yiwen; Yang, Yingying; Lin, Xuechun Source: Chaos, Solitons and Fractals, v 180, March 2024;

Abstract:

The developed pulse shaping technology based on fourth-order dispersion (FOD) has emerged as an effective platform for exploring nonlinear dynamics and non-equilibrium processes in physics. Additionally, the pure-quartic soliton (PQS), enabled by a delicate balance between FOD and nonlinearity in the medium, offers a promising new avenue for generating high-energy pulses. Thus, there is a strong desire to conceive a quartic-dispersion-dominant mode-locked fiber laser to study the generation and evolution dynamics of PQSs under high pump power. In this paper, we report on the PQS collapse effect in a net anomalous dispersion mode-locked fiber laser for the first time. Through solving the generalized nonlinear Schr？dinger equation (GNLSE) with high-order dispersion, a quartic-dispersion-dominant mode-locked fiber laser is theoretically established and the PQS generation is investigated. Our findings reveal that the PQS collapse effect is induced by excessive pump strength and the uncompensated nonlinearities, and eventually leads to the emergence of PQS packets. The higher the pump power, the more obvious the soliton collapse effect. Furthermore, our research sheds light on the significant contribution of high-order dispersion in expanding our understanding of solitons inside a fiber laser.

？ 2024 Elsevier Ltd (29 refs.)