Nonlinear optical absorption properties of zirconium selenide in generating dark soliton and dark-bright soliton pairs.

Our work reports the preparation of zirconium selenide ()-polyvinyl alcohol (PVA) film-type saturable absorber (SA) and its nonlinear absorption performance in obtaining dark soliton and dark-bright soliton pairs in an Er-doped fiber (EDF) laser for the first time, to the best of our knowledge. The saturation intensity and modulation depth of the - SA were ∼12.72/ and 2.3%, respectively. Due to the modulation of the SA, under a pump power of 525.2 mW, stable dark soliton operation with an average output power of 9.75 mW, and a pulse repetition frequency of 20.84 MHz, a pulse width of 3.85 ns was attained successfully. By adjusting the state of the polarization controllers, dark-bright soliton pairs were also observed. To the best of our knowledge, this was the first demonstration focusing on the nonlinear optical absorption applications of in obtaining dark soliton and dark-bright soliton pairs. Our results show that is a good two-dimensional SA material for acting as an ultrafast optical device due to its suitable nonlinear optical absorption properties.