通过湿化学方法制备了具有三阶非线性光学性质的硒化铅/聚乙烯醇复合物薄膜.采用透射电镜和扫描电镜对硒化铅量子点的尺寸和薄膜的形貌进行表征.运用Z扫描方法，研究了薄膜在波长为532 nm,脉冲宽度为38 ps条件下的三阶非线性光学性质.实验结果表明：合成的硒化铅量子点尺寸在10 nm左右，属于强量子受限，制备的薄膜表面粗糙度比较好；薄膜在皮秒脉冲激光作用下呈现负的非线性折射效应和反饱和吸收性质，其三阶非线性极化率χ(3)为3.6×10－11 esu.

PbSe/polyvinyl alcohol composite film with third-order nonlinear optical property was prepared by wet-chemical method. The morphology of the PbSe nanocrystals was characterized by transmission electron microscope, and the surface morphology of the composite film was characterized by scanning electron microscope. The third-order optical nonlinearity of film was investigated by using the laser Z-scan technique with 38 ps pulses width at 532 nm. The experimental results show that the diameter of PbSe nanocrystals is about 10 nm, which is in strong quantum confinement regime, and the film has a flat surface. Negative nonlinear refraction and reverse saturable absorption properties were observed, the third-order nonlinear refractive index χ(3) was found to be 3.6×10－11 esu.