2-μm mode-locked nanosecond fiber laser based on MoS₂ saturable absorber

We demonstrated a 2-μm passively mode-locked nanosecond fiber laser based on a MoS₂ saturable absorber (SA). Owing to the effect of nonlinear absorption in the MoS₂ SA, the pulse width decreased from 64.7 to 13.8 ns with increasing pump power from 1.10 to 1.45 W. The use of a narrow-bandwidth fiber Bragg grating resulted in a central wavelength and 3-dB spectral bandwidth of 2010.16 and 0.15 nm, respectively. Experimental results show that MoS₂ is a promising material for a 2-μm mode-locked fiber laser.