甲基蓝-钛酸盐纳米聚合物薄膜的光谱和光学非线性研究

Spectral and optical nonlinear characteristics of methylene blue-titanate nanohybrid film

为了满足光学非线性器件设备对工作材料的要求,探究具有高阶非线性效应的固态薄膜材料的制备方法,并对其光学特性进行表征,采用化学插入法,将甲基蓝染料分子插入到具有纳米量级的层状钛酸盐片间,制备了甲基蓝-钛酸盐纳米聚合物薄膜,通过吸收光谱和荧光光谱的测定,发现薄膜的吸收峰相对于染料溶液发生了明显的蓝移,表明染料分子在纳米片间是H-聚集排列。进一步应用单光束连续He-Ne激光Z-扫描技术研究了样品的非线性光学特性,结果显示:插入染料分子的钛酸盐纳米MB/HTO聚合物薄膜具有"负"的非线性折射率,在低功率连续激光作用下聚合物薄膜的非线性折射率系数n2的量级为10-10m2/W。

The method for preparing solid thin films with high-order nonlinear effects was explored,and the optical properties of the materials were investigated to obtain an ideal nonli-near optical device.The MB/HTO nanohybrid thin film was prepared by intercalating reaction between the dye and titanate nanosheets.The spectral characteristics of methylene blue dye before and after intercalating into layered titanate nanosheets and forming a nanohybrid thin film were investigated by measuring absorption and fluorescence spectra.It was found that the absorption peak of the film generated a more obvious blue shift than that of the solution,which indicated the formation of H-aggregates of the dye in the interlayer space of nanosheets.In addition,the nonlinear optical properties were studied using single beam Z-scan technique under irradiation of low power continuous wave（CW） produced by He-Ne laser with a wavelength of 632.8 nm.The sample exhibited a negative（self-defocusing） nonlinearity and large nonlinear refractive index with an order of 10-10 m2/W.