Dissipative soliton operation in a mode-locked laser based on thulium-doped fiber

We report a dissipative soliton laser utilizing thulium-doped fiber as the saturable absorber. By adjusting the polarization controller and pump power, a stable fundamental dissipative pulse has been successfully achieved, featuring a center wavelength of 1565.88 nm, a 3-dB bandwidth of 1.20 nm, a repetition frequency of 36.9 MHz, and a signal-to-noise ratio of 64 dB. Combined the gradual increase of the pump power with the intracavity polarization optimization, the spectral morphology evolves into a parabolic shape, Π-shape, and M-shape. Moreover, through increasing the gain, multiple dissipative pulses include dissipative soliton pairs and triples are manifested because of the peak power clamping effect. The repetition frequencies are 73.8 MHz and 110.7 MHz, respectively, with signal-to-noise ratios both more than 60 dB, indicating that the constructed dissipative soliton laser has excellent stability. This study not only enhances the understanding of the nonlinear dynamic process of dissipative soliton generation, but also offers a novel approach for designing ultrafast lasers characterized by high stability and an all-fiber structure.