【作者】 张磊；

【导师】 张学进；

【作者基本信息】 南京大学 ， 材料工程（专业学位）， 2016， 硕士

【摘要】 随着微纳加工技术的不断发展,制备尺寸更小、精度更高的微纳结构成为现实。基于微纳金属结构的表面等离激元光子学也展现了其丰富的物理内涵与应用前景。由于表面等离极化激元与局域表面等离激元会在金属与介质界面产生很强的电场增强效应,因此被广泛地应用在表面增强拉曼散射、生物传感、非线性光学等领域。本文主要研究了低损耗一维银纳米光栅结构的光学特性,以及在表面增强拉曼散射效应的应用。本文的研究内容可以分为以下两个方面：1.介绍了低损耗一维银纳米光栅结构的制备方法并对其进行了表征。利用聚焦离子束刻蚀的方法在硅片上加工出一维纳米光栅结构；用磁控溅射镀膜的方法在硅片上镀一层银纳米薄膜；在银膜上电镀铜衬底后将金属层揭下得到了较为光滑的一维银纳米光栅结构。另外用聚焦离子束刻蚀的方法在磁控溅射银膜上加工了相同参数的结构,并对两种方法得到的银纳米光栅结构用电子扫描显微镜和原子力显微镜做了表征。2.研究了不同制备工艺,具有相同结构参数的一维银纳米光栅结构的光学特性,并应用到了表面增强拉曼散射效应上。用时域有限差分法对一维光栅结构的参数进行了优化,获得一维银纳米光栅结构较强的局域电场。实验测量了上述两种工艺得到的光栅结构的色散关系和表面等离激元的传播长度。得到光滑表面的一维银纳米光栅具有更长的传播长度,即更小的光学损耗。进一步通过表面增强拉曼散射得到,表面光滑,低损耗的一维银纳米光栅结构比普通工艺得到的银纳米光栅结构其拉曼信号增强了约50倍。我们的低损耗一维银纳米光栅结构可以作为一种有效的SERS基底,具有广阔的应用前景。更多还原

【Abstract】 Various metallic nanostructures with smaller size and higher accuracy have been designed and fabricated out due to the increasing advances in nano-fabrication techniques. Surface plasmons supported by metallic nanostructures exhibits considerable novel physical effect of optics. The coupling between surface plasmon polarization and localized surface plasmon can further enhance the local electric field at metal and dielectric boundary, which holds great potential for applications in the research fields of surface enhanced Raman scattering (SERS), biosensors, and nonlinear optics.In this thesis, we will give detailed studies on the optical properties of one dimensional silver nanograting structure with low optical loss and its application on SERS. The thesis is mainly composed of two sections that are arranged as following:1. The methods for the preparation of low loss one-dimensional silver nanograting structure and its structural characterization are introduced. We first use focused ion beam (FIB) technology to fabricate one-dimensional dielectric nanograting structure on a silicon wafer. Than using magnetron sputtering method, silver film on the surface is deposited. Finally, copper plating on the silver film and peeled the metal film together, the one-dimensional silver nanograting structure with smooth surface is achieved. We also use FIB technology to prepare the corresponding one-dimensional silver nanograting structure with rough surface directly on silver films deposited on a silicon wafer by magnetron sputtering method. Both the two nanostructures are characterized by scanning electron microscope (SEM) and atomic force microscopy (AFM).2. We investigate the optical properties of one dimensional silver nanograting structure with low optical loss and its application on SERS. We use FDTD method to optimize structural parameters of the one-dimensional silver nanograting for achieving strong enhanced local electric field. The dispersion relation and surface plasmon propagation length of the above two one-dimensional silver nanogratings are investigated both experimentally and theoretically. The one-dimensional silver nanograting with smooth surface has a longer propagation length, which exhibits less optical loss. Further through SERS experiment, the enhancement factor of the one-dimensional silver nanograting with smooth surface is increased by about 50 times compared to the one-dimensional silver nanograting with rough surface. Our low loss one-dimensional silver nanograting structure with smooth surface can serve as an effective SERS substrate.更多还原