中文摘要：

本文应用离散偶极子近似方法计算了十字形银纳米结构的消光光谱及其近场电场强度分布.研究表明相比于单根纳米棒,十字形纳米结构能够提供更强的表面电场;由于相邻凸起间的电场耦合作用,当入射光的偏振方向改变时,在十字形纳米结构的侧表面总能激发出较强的电场.另外,本文还系统地研究了十字形纳米结构的形貌参数对其表面等离子体共振峰的影响.这些结果将会指导十字形纳米结构的制备,以满足其在表面增强拉曼散射中的应用.

英文摘要：

The extinction spectra and the electric field distributions of the cross-shaped nanostructures are calculated by the discrete dipole approximation method.Compared with the individual nanorod,the cross-shape nanostructure can generate high local electric fields at the lateral surface.Because of the electric field couplings between adjacent protruding parts,much enhanced electric fields always occur at the lateral surface of the cross-shape nanostructure,with the incident polarization direction varied.In addition,the effects of the structural parameters of the cross-shape nanostructures on their plasmonic properties are also investigated.These results would guide the preparation of the cross-shape nanostructures for their applications in surface enhanced Raman scattering.