Dynamic Pulsating Behaviors of Mode-locked Pulses in an Ultrafast Erbium-doped Fiber Laser

This paper reports the experimental observation of the pulsating pulses in a passively mode-locked erbium-doped fiber laser with the nonlinear polarization rotation structure. In addition, the corresponding pulse dynamics can be further explored by using dispersive Fourier transform (DFT) technique. The study indicates that these pulses show a pulsation process with a typical period of ~167 roundtrips, which can make them generate more pulse energy. We believe that the above results can be beneficial to further understand the NLPs and achieve high-energy pulses in fiber lasers.