Solution processed MoS^sub 2^-PVA composite for sub-bandgap mode-locking of a wideband tunable ultrafast Er:fiber laser

We fabricate a free-standing few-layer molybdenum disulfide (MoS^sub 2^)-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1,535 nm to 1,565 nm, are generated, corresponding to photon energies below the MoS^sub 2^ material bandgap. These results contribute to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications. [Figure not available: see fulltext.]