Passively Q-switched Erbium-doped and Ytterbium-doped fibre lasers with topological insulator bismuth selenide (Bi2Se3) as saturable absorber

This paper portrays a simple Q-switched Erbium-doped fibre (EDF) and Ytterbium doped fibre (YDF) lasers by using topological insulator (TI) Bismuth Selenide (Bi2Se3) as saturable absorber. The modulation depth of the fabricated Bi2Se3 is about 39.8% while its saturating intensity is about 90.2 MW/cm2. By depositing the TI Bi2Se3 SA onto fibre ferrules and incorporate it inside the proposed cavity, a stable Q-switching operation was achieved at 1 μm and 1.5 μm. The fabricated Bismuth Selenide (Bi2Se3) as saturable absorber (SA) is a broadband SA where it offers a compact and low cost fabrication which is beneficial in various photonic applications.