Tin monoselenide based saturable absorbers for the generation of ultrashort pulses

Abstract

The IV-VI semiconducting compounds, a family of two-dimensional material with attractive optical and electrical properties, have received extensive attention in recent years. Here, we demonstrate that tin monoselenide (SnSe) can be utilized as a saturable absorber (SA) for erbium-doped fiber laser (EDFL). By sandwiching the film of polyvinyl alcohol (PVA) and SnSe between two fiber connectors and depositing the SnSe nanoparticles onto the side-polished fiber (SPF), two types of SnSe based SAs are fabricated. The nonlinear optical properties of these two SAs are investigated, the modulation depth of the SnSe-SPF and SnSe-PVA SAs are 19.5% and 16.8%, respectively. Stable soliton mode-locking operations with center wavelength of 1556.6 (1558.2) nm and pulse width of less than 2 ps are obtained in the EDFL based on SnSe-SPF (SnSe-PVA) SA. Furthermore, the experimental results confirm that the damage threshold of the SnSe-SPF SA is much higher than that of the SnSe-PVA SA. Numerous photonics devices may benefit from the nonlinear saturable absorption properties of SnSe, such as near-infrared pulsed lasers, modulators, and so on.