High-power passively Q-switched Yb-doped fiber laser based on Tin selenide as a saturable absorber

In this paper, tin selenide (SnSe2) is proposed as a saturable absorber (SA) for demonstrating a dual-wavelength passively Q-switched Yb-doped fiber laser. A film-type SnSe2-PVA SA was successfully prepared by incorporating the SnSe2 nanosheets with the polyvinyl alcohol. The nonlinear absorption properties of the SA were investigated within a Yb-doped fiber laser. Stable passively Q-switched pulse operation with a maximum output power of 18.03 mW under pump power of 680 mW was generated, and the minimum pulse duration was 966 ns under a pulse repetition rate of 168.7 kHz, corresponding to a pulse energy of 106.9 nJ. Thereinto, 18.03 mW, 168.7 kHz and 966 ns were all the recorded parameters obtained within a 2D material-based passively Q-switched ring-cavity Yb-doped fiber laser. The excellent results proved that SnSe2 has well-matched nonlinear absorption properties in comparison with other reported transition metal dichalcogenides, Thus, wide-ranging important potential applications of SnSe2 in the field of ultrafast optics will soon be recognized.