Hafnium diselenide as a Q-switcher for fiber laser application

Group IVB (Hf) transition metal dichalcogenides (TMDs) have attracted significant interest in photoelectronics due to their predictable superior physical characteristics. In this work, the liquid phase exfoliation method is used to prepare the hafnium diselenide (HfSe₂)/polyvinyl alcohol (PVA) saturable absorber (SA) device. The modulation depth (ΔT) is measured to be 6.65%. By using HfSe₂/PVA as a Q-switcher, application in the fiber laser with the Q-switching state is demonstrated experimentally. The maximum single pulse energy is 167 nJ is and the slope efficiency is 7.7%. To our best knowledge, this is the first report of the use of HfSe₂ as SA for large energy pulse generation. The experimental results prove that, because of its excellent nonlinear optical absorption properties, HfSe₂ could promote the development of Hf-based TMDs in the field of ultrafast photonics.