▎ 摘　　要

In this paper, we aimed to investigate the linear and nonlinear optical properties of GO-ZnO and RGO-ZnO nanocomposites in comparison with pure GO and reduced graphene oxide (RGO). For this purpose, GO, RGO, GO-ZnO, and RGO-ZnO were synthesized and characterized by Fourier transform infrared (FT-IR), Ultraviolet-Visible (UV-Vis) absorption, X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). XRD and EDX analysis indicated the reduction of GO as well as the successful synthesis of GO-ZnO and RGO-ZnO nanocomposites. The FT-IR spectroscopy showed that absorption bands were at 3340 cm(-1) , 1630 cm(-1) , 1730 cm(-1) and 480 cm(-1)related to OH, C=C, C=O, and Zn-O stretching vibrations, respectively. The direct band gaps of GO, RGO, GO-ZnO and RGOZnO from UV-Vis spectra were at 3.36, 3.18, 3.63 and 3.25 eV, sequentially. Moreover, the third-order nonlinear optical properties were investigated using a z-scan technique with Nd: YAG laser (532 nm, 70 mW). It can be seen that the nonlinear absorption coefficient value (beta) increased from 5.3 x 10(-4)(GO) to 8.4 x 10(-3) cm/W (RGO-ZnO). In addition, nonlinear refractive index (n(2)) of the GO, RGO, GO-ZnO, and RGO-ZnO was obtained as 10.9 x 10(-10), 14.3 x 10(-10), 22.9 x 10(-10), and 31.9 x 10(-10) cm(2)/W respectively.