中文摘要：

研究了在准静态极限下,各向异性介电核-金属壳层这种特殊核-壳结构的表面增强拉曼散射的特性.首先,基于第一性原理,我们推导出这个带壳纳米球颗粒的多重极化率,然后运用Gersten-Nitzan模型研究了这个结构的表面增强拉曼散射的特性.在本文中,我们针对这种各向异性介电核-金属壳层的纳米球颗粒的结构进行理论计算和数值模拟,结果显示,介电核中径向各向异性特性的引入,会对该纳米颗粒的表面增强拉曼散射的峰值起到增强的作用,同时还可以调节体系表面等离共振频率.此外,我们还研究了核的大小对表面增强拉曼散射的意义.我们的研究对于未来探索具有各向异性特性结构的受激拉曼散射很有意义.

英文摘要：

We develop a full-wave electromagnetic theory of surface enhanced Raman scattering（SERS） from Ag-coated nanoparticles with radial anisotropy in the quasi-static limit.The multipolar polarizability of the anisotropic coated nanoparticle is derived based on the first-principles approach,and then we employ the Gersten-Nitzan model to investigate SERS from Ag-shell and radially anisotropic-core nanoparticles.It is found that the introduction of radial anisotropy into the core of the nanoparticle provides a novel approach to achieve enhanced SERS peaks and tailors the surface plasmon resonant frequencies.Also,the dependence of the SERS spectra upon the size effect is also addressed.Our investigation can be applied in prospective stimulated Raman scattering schemes especially for anisotropic nanoparticles.