Concentration effect of dispersed-graphene based saturable absorber on stabilizing and shortening mode-locked pulse

We investigated the concentration effect of dispersed graphene in polymer films for being a saturable absorber (SA) to optimize the mode locking performance of the Erbium-doped fiber (EDFL) laser pulse. With the concentrations of 1.65 and 3.25 wt%, the mode-locked (ML) pulse is stabilized with the pulse duration of 543 and 443 fs, respectively. For a short pulse of 443 fs, the 3-dB spectral bandwidth and time-bandwidth product were 5.78 nm and 0.316, respectively.