title: Wideband saturable absorption in few-layer molybdenum diselenide (MoSe₂) for Q-switching Yb-, Er- and Tm-doped fiber lasers.
abstract: We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap saturable absorption in MoSe2, which is explained in the context of edge-states, building upon studies of other semiconducting transition metal dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2 to the growing catalog of TMDs with remarkable optical properties, which offer new opportunities for photonic devices.
authors.forename: R I
authors.initials: RI
authors.lastname: Woodward
authors.forename: R C T
authors.initials: RC
authors.lastname: Howe
authors.forename: T H
authors.initials: TH
authors.lastname: Runcorn
authors.forename: G
authors.initials: G
authors.lastname: Hu
authors.forename: F
authors.initials: F
authors.lastname: Torrisi
authors.forename: E J R
authors.initials: EJ
authors.lastname: Kelleher
authors.forename: T
authors.initials: T
authors.lastname: Hasan