Mechanism of formation of noiselike pulses in passively mode-locked fiber lasers

We present the results of an analysis of noiselike pulses generated in passively mode-locked fiber lasers with anomalous dispersion. The master equation used for the analysis takes into account the gain saturation, the quadratic frequency dispersion of the gain and the refractive index, and the cubic-quintic nonlinearity of the losses and refractive index. Reasons for the stabilization of noiselike pulses are investigated. It is found that the space-time localization of a noiselike pulse is associated with the suppression of single solitons located outside this pulse. The mechanism of such competition between single solitons and a noiselike pulse is determined.