Z扫描法测单壁碳纳米管薄膜非线性特性的研究

为研究单壁碳纳米管(SWCNT)薄膜的三阶非线性光学性质,采用旋转涂覆法在石英玻片上制备出包含SWCNT和聚甲基丙烯酸甲酯(PMMA)的聚合物薄膜。测得薄膜的线性透射谱,并观察了薄膜的表面形貌。为提高测量SWCNT薄膜三阶非线性系数的准确度,研究了Z扫描法测量材料的非线性系数时相关参量变化对测量准确度的影响,并搭建Z扫描系统,研究了自制薄膜的三阶非线性光学性质。通过对实验数据的模拟和计算,得到自制碳纳米管薄膜的非线性吸收系数(β)、三阶非线性折射系数(γ)分别为-7.8×10-7 cm/W、-6.4×10-11 cm2/W,三阶非线性极化率为2.06×10-9 esu。证明SWCNT/PMMA薄膜具有较强的非线性光学特性。

Research on Nonlinear Characteristics of SWCNT Film by Z-Scan Method Measurement

In order to study the third order nonlinear optical property of single-walled carbon nanotube(SWCNT) film,we prepare polymer film of SWCNTs and poly methyl methacrylate(PMMA) on quartz substrate by rotation coating.We obtain linear transmission spectrum and surface morphology of the film.For improving the measurement accuracy of the third order nonlinear coefficient of SWCNT polymer film,we discuss the influence of the changes in related parameters of the Z scanning method upon the measurement accuracy of the material nonlinear coefficient,and build Z scanning system to study the third order nonlinear optical properties of the thin film.Through the simulation and calculation of experimental data,we obtain that the third order nonlinear absorption coefficient(β) and the third order nonlinear refractive coefficient(γ) of this SWCNT film are-7.8×10-7 cm/W and-6.4×10-11 cm2/W,respectively,and the third order nonlinear susceptibility is 2.06×10-9 esu.The results prove that SWCNT/PMMA film owns strong nonlinear optical properties.