中文摘要：

利用静电自组装技术，以生物大分子材料壳聚糖杂化处理具有稳定结构的CdSe／ZnS核／壳量子点，形成复合多层薄膜．与薄膜的吸收谱线比较，在375nm飞秒激光激发下测量的量子点的光致发光谱存在Stokes位移．采用Z扫描技术，利用790nm飞秒激光研究了其三阶非线性吸收和折射特性，发现饱和吸收信号来自CdSe／ZnS量子点，而自聚焦的折射信号则部分来自壳聚糖．测出多层膜的三阶非线性系数分别是β=6．5×10^-6cm／W，n2=1．5×10^-10cm^2/W。

英文摘要：

Biopolymer-CdSe/ZnS core-shell quantum dot hybrid films were prepared using self-assembly technique. Compared with the absorbance spectrum, the photoluminescence excited by laser with λ= 395nm has Stokes shift. The third-order nonlinear optical properties of biopolymer-CdSe/ZnS film were studied by Z-scan setup with femtosecond laser at 790nm. It is found that the nonlinear absorptive signal partially originates from Cde/ZnS quantum dots while the nonlinear refractive signal partially originates from biopolymer chitosan. The magnitudes of them are measured to be ,β = 6.5 × 10^-6cm/W and n2 = 1.5 ×10^-10cm^2/W, respectively.