Multi-element two-dimensional compounds Pb3Sn4FeSb2S14 as saturable absorber to demonstrate large-energy mode-locked pulse generations

With liquid phase exfoliation method, Pb3Sn4FeSb2S14- polyvinyl alcohol film was prepared and its nonlinear optical properties were studied, the saturable intensity and the modulation depth of Pb3Sn4FeSb2S14 saturable absorber were 18.66 MW/cm2 and 3.94 %, respectively. When inserting the Pb3Sn4FeSb2S14- polyvinyl alcohol film into an Er-doped fiber laser as saturable absorber, the large-energy mode-locked operation was obtained easily. Stable mode-locked pulses were generated at 1560.84 nm with a maximum average output power of 14.16 mW, and the corresponding maximum pulse energy was 38.56 nJ. The experimental results proved that Pb3Sn4FeSb2S14 nanosheets with excellent nonlinear optical property could be competitive saturable absorber for large-energy pulsed fiber lasers.