Passively Q-switched erbium-doped fiber laser based on SnS_2 saturable absorber

Layered metal dichalcogenides (LMDs) have been extensively employed as saturable absorbers (SAs) for demonstrating passively Q-switched or mode-locked lasers due to the advantages of wide absorption range and ultra-fast recovery time. In this paper, the nonlinear saturable absorption property of another IV-VI LMDs tin disulfide (SnS2) was investigated. SnS2-polyving alcohol (PVA) film was successfully prepared and employed as a SA for demonstrating an Er-doped passively Q-switched fiber laser. Under a pump power of 637 mW, the maximum average output power was 9.33 mW. The minimum pulse width was as narrow as 510 ns, which, to our knowledge, is the narrowest pulse width obtained within passively Q-switched Er-doped all-fiber ring-cavity lasers. The results indicate that film-type SnS2-PVA SA has excellent nonlinear absorption properties and outstanding performance in obtaining short-pulse passively Q-switched operation, which will promote the practical applications of SnS2 in the field of ultrafast photonics.