The impact of third-order dispersion on the output characteristics of mode-locked fiber laser with near-zero group velocity dispersion

Ultrafast fiber lasers have attracted significant attention due to their high peak power and small pulse width. However, their performance is critically influenced by higher order dispersion effects, particularly third-order dispersion. In this work, the impact of third-order dispersion on the output characteristics of mode-locked ultrafast fiber lasers was investigated in a cavity with positive near-zero group velocity dispersion. The third-order dispersion was adjusted from 0 to 3.5 ps³ · km⁻¹ in numerical simulations in order to explore its influence on the pulse and spectral characteristics. Influences of third-order dispersion on the pulse shape and spectral sidebands were analyzed and explained with group delay and phase relationship. Additionally, limited compensation of third-order dispersion by group-velocity dispersion was discovered. These findings can provide a reference for the optimization of pulse characteristics in ultrafast fiber lasers.