title: Tunable Q-switched fiber laser based on saturable edge-state absorption in few-layer molybdenum disulfide (MoS₂).
abstract: We fabricate a few-layer molybdenum disulfide (MoS₂) polymer composite saturable absorber by liquid-phase exfoliation, and use this to passively Q-switch an ytterbium-doped fiber laser, tunable from 1030 to 1070 nm. Self-starting Q-switching generates 2.88 μs pulses at 74 kHz repetition rate, with over 100 nJ pulse energy. We propose a mechanism, based on edge states within the bandgap, responsible for the wideband nonlinear optical absorption exhibited by our few-layer MoS₂ sample, despite operating at photon energies lower than the material bandgap.
authors.forename: R I
authors.initials: RI
authors.lastname: Woodward
authors.forename: E J R
authors.initials: EJ
authors.lastname: Kelleher
authors.forename: R C T
authors.initials: RC
authors.lastname: Howe
authors.forename: G
authors.initials: G
authors.lastname: Hu
authors.forename: F
authors.initials: F
authors.lastname: Torrisi
authors.forename: T
authors.initials: T
authors.lastname: Hasan
authors.forename: S V
authors.initials: SV
authors.lastname: Popov
authors.forename: J R
authors.initials: JR
authors.lastname: Taylor