Graphene-Bismuth Telluride Nanocomposite Saturable Absorber for Passively Q-switched Erbium-doped Fiber Laser

A successful simple fabrication of graphenebismuth telluride $(\mathbf{Bi}_{2}\mathbf{Te_{3}})$ nanocomposite film was done by using liquid-phase exfoliation method. The composite film is applied as saturable absorber (SA) in which efficient passively Q-switched erbium-doped fiber laser operation is demonstrated. The minimum pulse width is recorded at $\displaystyle \mathbf{3.56\ \mu s}$ with a pulse repetition rate of 105 kHz.