In this paper,the characteristics of soliton in a passively mode-locked Er-doped fiber laser modeled by a non-distributed model are numerically investigated with the split-step Fourier method.Based on the analysis and model,sech2-shaped soliton is obtained by controlling the group velocity dispersion(GVD)and small-signal gain of the gain fiber.The law that the dispersion influences the characteristics of soliton in the mode-locked fiber laser is researched in net-cavity averaged anomalous dispersion regime.
