Pulse Evolution Characteristics In Self-Similar Mode-Locked Fibre Laser

A self-similar mode locked fibre laser is studied on a numerical model. By introducing a dimensionless factor k to characterize the pulse shape, the self-similar pulse evolution, formation and the temporal and spectral shape changes due to the elements in the cavity are investigated throughout the laser cavity. The results show that in the self-similar mode locked fibre laser, self-similar pulse is first formed in the single-mode fibre, which is then amplified in the gain fibre. Gain bandwidth has a small influence on pulse shape, so high energy self-similar pulse can be obtained after amplifacation. Because net cavity dispersion directly influences the pulse self-similar evolution, is very important to control the net cavity to a certain range to obtain self-similar pulses.