title: Yb- and Er-doped fiber laser Q-switched with an optically uniform, broadband WS2 saturable absorber.
abstract: We demonstrate a ytterbium (Yb) and an erbium (Er)-doped fiber laser Q-switched by a solution processed, optically uniform, few-layer tungsten disulfide saturable absorber (WS2-SA). Nonlinear optical absorption of the WS2-SA in the sub-bandgap region, attributed to the edge-induced states, is characterized by 3.1% and 4.9% modulation depths with 1.38 and 3.83 MW/cm(2) saturation intensities at 1030 and 1558 nm, respectively. By integrating the optically uniform WS2-SA in the Yb- and Er-doped laser cavities, we obtain self-starting Q-switched pulses with microsecond duration and kilohertz repetition rates at 1030 and 1558 nm. Our work demonstrates broadband sub-bandgap saturable absorption of a single, solution processed WS2-SA, providing new potential efficacy for WS2 in ultrafast photonic applications.
authors.affiliation: School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China.
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, Cambridge, CB3 0FA, UK.
authors.forename: Guohua
authors.initials: G
authors.lastname: Hu
authors.affiliation: School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Hu
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, Cambridge, CB3 0FA, UK.
authors.forename: R C T
authors.initials: RC
authors.lastname: Howe
authors.affiliation: Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronics Engineering, Shenzhen University, Shenzhen, 518060, China.
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.affiliation: School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China.|Collaborative Innovation Center of Geospatial Technology, Wuhan, 430079, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, Cambridge, CB3 0FA, UK.
authors.forename: T
authors.initials: T
authors.lastname: Hasan