Sn-doped Bi2Te2Se as a broadband saturable absorber for Q-switched fiber lasers

Passively Q-switched fiber lasers based on low-dimensional saturable absorbers have been extensively developed due to their efficiency, robustness and great simplicity [1]. However, an environmentally stable, industrial class lasers are still lacking. Here, we present a new material for the application as a broadband saturable absorber for large-energy Q-switched ytterbium- and erbium-doped fiber lasers. Bi
2
Te
2
Se:Sn is a small band gap semiconductor and ternary topological insulator [2]. It is characterized by broadband saturable absorption [3].