Solution processed MoS2-PVA composite for sub-bandgap mode-locking of a wideband tunable ultrafast Er:fiber laser

Abstract

We fabricate a free-standing few-layer molybdenum disulfide (MoS 2 )-polymer composite by liquid phase exfoliation of chemically pristine MoS 2 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 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.

Theory of edge-state optical absorption in two-dimensional transition metal dichalcogenide flakes

“…Recent studies have demonstrated that the sub-bandgap absorption in s-TMD nanoflakes can be saturated, and exploited this effect in the development of ultrafast lasers operating in the near-infrared, corresponding to photon energies in the range 0.6-1.12 eV. [7][8][9][10][11][12]15 While a growing body of experimental work continues to substantiate the process of sub-bandgap absorption in s-TMDs, and practical applications of this phenomenon are being leveraged in the field of photonics, theoretical analyses are limited and the origin of sub-bandgap optical absorption remains an open question. Here, we develop an analytical theory, testing the hypothesis of edge-mediated absorption in s-TMDs to explain the phenomenon of sub-bandgap saturable absorption.…”

Photoluminescence from Liquid‐Exfoliated WS2 Monomers in Poly(Vinyl Alcohol) Polymer Composites

“…18 In addition, both MoS2-and MoSe2-filled composites have been used as saturable absorbers for the production of fiber lasers. [19][20][21][22][23] For composite applications, because large quantities of 2D nanosheets are usually required, probably the most suitable nanosheet production method is liquid phase exfoliation (LPE). In this method, layered crystals, usually in powdered form, are exfoliated by ultrasonication 24,25 or shear mixing, 26,27 usually in appropriate solvents or surfactant solutions.…”

Stable, Surfactant‐Free Graphene–Styrene Methylmethacrylate Composite for Ultrafast Lasers

“…requires SAs to show thermal and environmental stability (i.e., moisture absorption ≤1% by weight in high, ≥80%, humidity environment and glass transition temperature ≥120 °C, for polymers). [ 11 ] Carbon nanotubes (CNTs), [ 2,12,13 ] graphene [13][14][15] and recently, other 2D materials such as semiconducting transition metal dichalcogenides (MoS 2 , [ 16,17 ] WS 2 , [ 18 ] MoSe 2 [ 19 ] ) and black phosphorus [ 20,21 ] have emerged as promising SAs for ultrafast lasers. [ 2,[22][23][24] In CNTs, broadband operation is achieved by using a distribution of tube diameters, [ 2,22 ] while this is an intrinsic property of graphene.…”