通过溶剂热法合成了石墨烯-硫化镉(G-CdS)复合材料。利用X 射线衍射仪、透射电子显微镜和紫外可见光谱仪对G-CdS复合材料的结构、尺寸、形貌和吸收特性等进行了表征，结果表明硫化镉量子点的平均尺寸为7 nm，且较为均匀地附着在石墨烯上。利用单光束Z-扫描技术研究了G-CdS复合材料在波长为532 nm、脉冲宽度为30 ps激光作用下的三阶非线性光学特性，结果表明G-CdS复合材料具有正的非线性折射率和饱和吸收特性，其三阶非线性极化率为4.36×10^-12 esu，非线性吸收系数为-6.54×10^-11 m/W。与硫化镉量子点相比三阶非线性特性有较大改善。

Graphene- cadmium sulfide (G- CdS) composites are synthesized by a solvothermal method. The composites are characterized by X-ray diffraction, transmission electron microscopy and ultraviolet visible (UVvis) absorption on their structure, size and morphology, which demonstrate that cadmium sulfide quantum dots with an average diameter of about 7 nm attached to the graphene surface. The third-order optical nonlinearities of G-CdS composites using picosecond Z-scan technique at wavelength of 532 nm is investigated, pulse width of 30 ps. The results show that G-CdS composite has a positive nonlinear refractive index and properties of saturable absorption. The third-order nonlinear susceptibility of G-CdS composite is calculated to be 4.36×10^-12 esu, nonlinear absorption coefficient to be - 6.54 × 10^-11 m/W. Comparing with cadmium sulfide quantum dots, the third- order nonlinearity of composites are improved.