Preparation of ultrathin ReS
Indium selenide (InSe) is a typical layered metal-chalcogenide semiconductor that has potential for developing ultrafast optoelectronic devices. In this work, InSe-polyvinyl alcohol (InSe-PVA) film is employed as saturable absorber and prepared by mixing InSe solution and polyvinyl alcohol solution. The nonlinear absorption properties of the InSe saturable absorber (InSe-SA) are investigated, showing that the nonsaturable absorption and modulation depth are 37.5% and 9.55%, respectively. lasers are generated in erbium-doped fiber (EDF) laser-employed InSe as a mode-locker. The central wavelength and pulse duration of the pulse are 1568.73 nm and 2.06 ps, respectively, under a repetition rate of 1.731 MHz. The maximum average output power is 16.4 mW at the pump power of 413 mW. To the best of our knowledge, this is the first demonstration of a pulse with InSe as a mode-locker. The experimental results further demonstrate that InSe is an outstanding nonlinear absorption material in ultrafast .