Generation of dissipative soliton resonance and soliton rain in passively mode-locked fiber laser based on GeTe saturable absorber

We report the generation of dissipative soliton resonance and soliton rain in an Er-doped fiber laser based on GeTe as saturable absorber. When the pump power is 60 mW, the fiber laser achieved the stable dissipative soliton resonance mode-locked operation. The pulse width of the trapezoidal envelope pulses increases from 21 to 35.5 ns with the increase of the pump power, while keeping the pulse profile and intensity invariable. By properly adjusting the polarization controller, a stable soliton rain pulse is obtained at the pump power of 70.4 mW. With the increase of pump power, its average output power increased from 0.52 to 1.56 mW, and its corresponding fundamental repetition rate, central wavelength and 3-dB bandwidth is 3.21 MHz, 1562.6 nm and 2.74 nm, respectively. The experimental results demonstrate that GeTe nanosheets could be developed as an effective saturable absorber for ultrashort pulse fiber lasers.