Ag/WTe₂复合薄膜的非线性光学特性

Nonlinear Optical Properties of Ag/WTe₂ Composite Films

摘要: 本文利用磁控溅射技术成功制备出了WTe₂薄膜及Ag/WTe₂复合薄膜。并表征了两种薄膜的形貌特点及元素组成。紫外可见吸收光谱表明，Ag/WTe₂复合薄膜的吸收发生蓝移。拉曼光谱的特征峰证实了WTe₂薄膜的成功制备。在532 nm波长处，激发功率为1 μJ的开孔Z扫描测试中发现，两种薄膜的非线性吸收特性均表现出饱和吸收特性。计算结果表明相比于WTe₂薄膜，Ag/WTe₂复合薄膜的非线性吸收系数有了明显的增强，这是由于Ag纳米颗粒的等离激元效应，表明Ag纳米薄膜可以更好地提高复合薄膜非线性吸收特性。

Abstract: WTe₂ thin films and Ag/WTe₂ composite thin films were successfully prepared by magnetron sputtering technology. The morphology and ele-mental composition of the two films were characterized. The UV-Vis absorption spectra showed that the absorption of Ag/WTe₂ composite films was blue-shifted. The characteristic peaks of the Raman spectrum confirmed the successful preparation of WTe₂ thin films. At the wavelength of 532 nm, the open-hole Z-scan test with the excitation power of 1 μJ found that the nonlinear absorption characteristics of both films exhibited saturable absorption characteristics. The calculation results show that the nonlinear absorption coefficient of the Ag/WTe₂ composite film is significantly enhanced compared with the WTe₂ film, which is due to the plasmon effect of the Ag nanofilm, indicating that the Ag nanofilm can better improve the non-linear absorption of the composite film.