Ag/ZnTe复合薄膜在近红外区域的非线性特性
Ultrafast Nonlinear Properties of Ag/ZnTe Composite Films in the Near-Infrared Region

通过精确调控磁控溅射工艺参数，成功制备了一系列具有不同功率的银纳米基膜。随后，以这些基膜为生长平台，促进了具有不同结构特征的碲化锌薄膜的形成。通过扫描电子显微镜、原子力显微镜、拉曼光谱、X射线衍射及紫外–可见分光光度计等多种表征手段，全面研究了复合薄膜的微观结构、晶体质量及带隙特性。同时，利用四点探针法深入研究了样品的霍尔效应行为，系统分析了其电导性能。Z扫描实验结果表明，所制备的薄膜表现出优异的非线性吸收性能，且该性能可通过调控银纳米薄膜的溅射能量实现优化。基于飞秒Z扫描技术，我们进一步研究了复合体系在800纳米波长下的非线性光学特性。研究结果表明，纯碲化锌薄膜以及复合结构薄膜均表现出反饱和吸收现象与自散焦特性。值得注意的是，与纯碲化锌薄膜相比，复合薄膜的非线性光学性能显著提升。得益于其超快非线性光学响应特性，此类复合薄膜在光学限幅器与全光开关等实际应用领域展现出广阔的应用前景。
Ag nanofilm bases at different powers were prepared by adjusting the magnetron sputtering parameters, and the base film was used to induce the growth of ZnTe films with different structures. The morphology, crystal quality and bandgap of the composite films were characterized using scanning electron microscopy, atomic force microscopy, Raman spectroscopy, x-ray diffraction and UV-Vis spectrophotometer, and the Hall effect properties of the samples were evaluated using the four-point probe method. The z-scan tests revealed that these films have excellent nonlinear absorption properties, which can be tuned by the sputtering power of the Ag nanofilms. Nonlinear optical responses at 800 nm of the composite system Ag/ZnTe were further analyzed with a femtosecond Z-scan technique. In our results, it was clarified that both ZnTe and Ag/ZnTe films with composite structure exhibit RSA as well as self-dispersion behavior. Importantly, such composite films exhibited substantial improvements in nonlinear optical properties, contrast with single ZnTe films. These composite films with ultrafast nonlinear optical response will have a positive impact on practical applications such as optical limiter devices and all-optical switching devices.