Versatile preparation of ultrathin MoS_2 nanosheets with reverse saturable absorption response

High-yielded ultrathin MoS2 nanosheets (UMS) with thickness below 4 nm were successfully synthesized by a simple, cost-effective and reproducible solid-state reaction method. Significant reverse saturable absorption and nonlinear refraction responses of the UMS were measured by the z-scan experiment under femtosecond pulses at 800 nm. The figure of merit is calculated to be ~2.52 × 10−15 esu cm. Furthermore, optical limiting (OL) effects of the UMS were observed with low threshold FOL ~44 mJ/cm2. These results reveal that solid-state reaction is a feasible method for the fabrication of optical nanomaterials used in nanophotonic devices including optical limiter, which can be expanded to prepare other two-dimensional nanomaterials.