Dissipative Soliton Trapping in an All Normal Dispersion Mode-Locked Yb-Doped Fiber Laser

We report on an all-normal-dispersion Yb-doped fiber laser with mode-locking mechanism based on nonlinear polarization rotation. The splitting and trapping of dissipative solitons (DSs) could be observed by inserting of a short section of polarization-maintaining fiber in cavity configuration as an in-line birefringence fiber filter. Two trapped orthogonal polarization DSs can travel with the same group velocity in the laser cavity. With the DSs trapping, the polarization sidebands are appeared in the spectrum. The trapping of DSs and sideband generation is numerically simulated as well.