Facile synthesis of two-dimensional WS2 with reverse saturable absorption and nonlinear refraction properties in the PMMA matrix

We report a versatile, cost-effective and reproducible solid-state reaction approach to synthesize two-dimensional (2D) WS2 with strong nonlinear optical performances. The reverse saturable absorption and nonlinear refraction properties of 2D WS2 incorporated into PMMA were measured by the z-scan configuration under femtosecond pulses at 800 nm. The figure of merit and the nonlinear optical refractive index n2 were calculated to be ∼0.40 × 10−13 esu cm and ∼3.34 × 10−4 cm2/GW, respectively. Furthermore, optical limiting (OL) effects of the WS2/PMMA composite were observed with OL threshold FOL∼2.4 mJ/cm2, which is lower than those of previously reported OL materials. Such results imply the WS2/PMMA composite as a potential candidate for practical OL applications and the solid-state reaction technology provides a feasible approach for the preparation of 2D WS2 applied in the field of nanophotonics.