摘要
应用离散偶极子近似的方法计算了端-端相连直角排列的金银双纳米棒的表面等离子体共振耦合引起的消光光谱及其近场电场分布.研究表明对于金双纳米棒和银双纳米棒,在入射光的偏振方向与水平方向的夹角为45度时双体结构的消光谱峰位发生红移;当入射光的偏振方向与水平方向的夹角为135度时,由于表面等离子体强耦合作用,出现了两个新的等离子体共振模式.对于金银双纳米棒结构,由于表面等离子体耦合作用在偏振方向为45度和135度两种情况下,消光谱都出现双峰结构,但是偏振方向45度时长波表面等离子体共振峰出现更强的表面局域电场分布.这些结果对于贵金属纳米棒结构在表面增强拉曼散射方面有一定的参考意义.
The extinction spectra and field distribution of the surface plasmon coupling of Au-Ag nanorod dimers arranged end to end at right angles are calculated by the discrete dipole approximation. It is demonstrated that the peaks of extinction spectra will be red-shifted when the polarization direction of incident light is 45 degree angle between the horizon for Au nanorod dimers and Ag nanorod dimers. There are two new modes of plasmon resonance because of coupling in the dimers at 135 degree angle between the horizon of polarization direction of incident light. Surface plasmon coupling leads to two peaks of extinction spectra for Au-Ag nanorod dimers at 45 and 135 degrees of polarization direction of incident light. An enhancement of field distribution appears around Au-Ag nanorod dimers at 45 degree of polarization direction of incident light. The calculation results are expected to have potential applications in surface enhanced Raman scattering
出处
《广东技术师范学院学报》
2013年第7期12-16,共5页
Journal of Guangdong Polytechnic Normal University
基金
国家自然科学基金(61201102)
广东省自然科学基金(S2012040006347)
广东高校优秀青年创新人才培育项目(LYM10067)
广东技术师范学院校级科研项目(09KJQ10)
关键词
金银纳米棒
表面等离子体耦合
消光光谱
场分布
Ag-Au nanorods
surface plasmon coupling
extinction spectra
field distribution
