HfSe2-based Q-switched fiber laser with large energy pulse

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have been extensively researched as nonlinear optical absorption materials for pulse fiber lasers applications. Herein, the liquid phase exfoliation method is employed to obtain HfSe2 nanosheets, and HfSe2/polyvinyl alcohol (PVA) film is prepared, whose modulation depth (ΔT) is measured to be 12.37 %. When inserting HfSe2-based saturable absorber (SA) into the compact fiber cavity, stable Q-switching pulse train is established at 1558.8 nm. Setting pump power at 559 mW, the narrowest pulse width/largest single pulse energy is determined to be 1.883 μs/292.67 nJ. In comparison to the reported results recently, our laser performance is superior to other works. Our experimental results prove that HfSe2 can be developed as a valid saturable absorption material for pulse laser generation.