Generation of two types of pulses in a thulium-doped fiber laser

The rectangular noise-like pulse (NLP) and dissipative soliton resonance (DSR) were generated in a thulium-doped fiber laser based on a nonlinear optical loop mirror (NOLM). The NLP and DSR pulses could be switched in the fiber laser by properly manipulating the intracavitary polarization controller (PC). The two different states are investigated by using the optical spectrum and radio frequency spectrum. The center wavelength of NLP is 1930.11 nm with the 3-dB bandwidth of 12.19 nm, and aforesaid parameters of DSR is 1944.04 nm, 10.36 nm, respectively. The radio frequency spectrum of the NLP pulse has two sub-peaks obviously, corresponding to the unstable long pulse train in the time domain. These findings may contribute to distinguish two rectangular pulses and lucubrate the dynamics of the rectangular pulses.