Nonlinear optical properties of poly (vinyl alcohol) thin films doped with in-situ WSe2/rGO composite

WSe2/reduced graphene oxide (WSe2/rGO) composite has been synthesized by a facile solvothermal reaction and all the polyvinyl alcohol (PVA) films were prepared by simple drop casting method. The third order nonlinear optical (NLO) properties and optical limiting (OL) responses of WSe2/rGO solution and WSe2/rGO/PVA film were investigated using the Z-scan technique at 1064 nm and its second harmonic of 532 nm with 4 ns laser pulses. The results demonstrate that the third order NLO and optical limiting responses of the WSe2/rGO composite are significantly enhanced compared with WSe2, rGO and WSe2/GO composite, whether in the solution or in the PVA film. It can be attributed to the contribution of charge transfer process and synergistic effect between WSe2 and rGO moieties. Besides, the optical nonlinearity of WSe2/rGO/PVA film was larger than that of the WSe2/rGO solution. The WSe2/rGO/PVA film exhibits much larger nonlinear absorption coefficient (3.5 x 10(5) cm/GW) and much lower threshold value (0.25 J/cm(2)) with the input energy of 27 mu J at 532 nm. The results pave the way for the nonlinear optical properties with transition metal dichalcogenides (TMDs)/graphene composite in the optical limiting devices.

Automated summary

The WSe2/reduced graphene oxide composite prepared by solvothermal reaction showed significantly enhanced third order nonlinear optical and optical limiting responses, with even more pronounced optical nonlinearity in the PVA film. This suggests potential applications in nonlinear optical devices for transition metal dichalcogenides/graphene composites.