SrBi_2Ta_2O_9铁电薄膜的三阶非线性光学性能的研究

Third-order nonlinear optical properties of SrBi_2Ta_2O_9 thin films

采用射频磁控溅射法在石英玻璃衬底上制备出均匀透明的SrB i2Ta2O9(SBT)薄膜,根据透射谱计算表明薄膜样品厚度为349nm,线性折射率为3.05。以锁模Nd:YAG激光器作为光源,利用Z-scan技术测定了薄膜的非线性光学性能。结果表明薄膜的非线性折射率n2=2.56×10-8esu,非线性光吸收系数β=3.93×10-4esu,其三阶非线性极化率的实部和虚部分别为:Reχ(3)=8.29×10-9esu和Imχ(3)=1.08×10-9esu。

The SrBi2Ta2O9 thin films were prepared on quartz substrates by using the RF magnetron sputtering method. The thickness of the thin film is 349nm and the linear refractive index was 3.05. The third - order nonlinear optical properties of the films were measured by the Z - scan technique. The nonlinear refractive index n2 and the nonlinear absorption index fl at 532nm wavelength are 2.56 × 10^-8Sesu and 3.9 × 10^-4esu,respectively. The real part of the third -order nonlinear optical susceptibility X^（3） is 8.29 × 10^-9esu and its imaginary part is 1.08 × 10^-9esu .