Niobium diselenide nanosheets for a vector soliton fiber laser

Niobium diselenide (NbSe2), an emerging group VB transition metal dichalcogenide, has been widely used in materials science, chemistry, and physics, while the applications of NbSe2 in ultrafast photonics are still rare. In this study, a NbSe2-based saturable absorber (NbSe2-SA) is proposed by depositing NbSe2 nanosheets on the surface of a microfiber, whose modulation depth is up to 8.8%. Based on the NbSe2-SA, conventional solitons with an ultrashort pulse duration of 697 fs are achieved, which are proved to be polarization-locked vector solitons by further study. The results show that group VB transition metal dichalcogenides, including NbSe2, could be developed as effective SAs for generating ultrafast pulses, especially vector pulses.