金属纳米颗粒聚合体中多重Fano共振效应的研究

项目名称： 金属纳米颗粒聚合体中多重Fano共振效应的研究

项目编号： No.11304219

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 刘绍鼎

作者单位： 太原理工大学

项目金额： 25万元

中文摘要： 金属表面等离激元Fano共振对降低辐射衰减、增大局域场强、提高传感性能具有重要意义，可控谱线整形是实现众多应用的核心。与单一Fano共振相比，多重Fano共振可实现多波段谱线整形，但现有体系对称性不高，多重Fano效应的产生依赖入射场偏振，且其调制深度较低，共振频率不易可控调整，限制了多波段谱线整形的应用。 多极表面等离激元共振频率容易调整、辐射衰减特性丰富。本项目提出在聚合体中引入多极表面等离激元模式耦合，同时利用聚合体的对称性，产生偏振无关的多重Fano效应。通过调节体系结构改变多重Fano共振的调制深度，有效降低辐射衰减、增大局域场强，在可见-近红外区域实现多波段可控谱线整形。本研究将利用时域有限差分法模拟体系近场和远场分布特性，并采用分子点群理论分析产生多重Fano共振的机理。最后结合以上成果，研究其在多波长传感方面的应用。本项目将为开发基于Fano共振的多波长生物传感器提供基础。

中文关键词： Fano共振；局域表面等离激元共振；聚合体；暗态；分子点群理论

英文摘要： Fano resonances in plasmonic nanostructures are very important for reducing radiative damping, near field enhancement, and the improvement of sensing performance, where the controllable plasmon line shaping plays a key role. Compared with a single Fano resonance, a system with multiple Fano resonances can realize controllable plasmon line shaping at several spectral positions, but present studies have not consider structure symmetry, the reported results show that multiple Fano resonances dependent on the polarization direction, the modulation depth is weak, and it is hard to adjust the resonance frequencies, which are the disadvantages for multiwavelength plasmon line shaping. It is easy to modify the frequency of multipolar localized surface plasmon resonance, and they have different radiative damping. In this project, metallic nanoparticle oligomer clusters will be investigated, and we propose that polarization independence multiple Fano resonances can be generated through the coupling between multipolar localized surface plasmon resonances, as well as the adjustment of structure symmetry. In order to realize controllable plasmon line shaping at several spectral positions in the visible-near infrared region, the modulation depth of multiple Fano Resonances will be modified by adjusting the structure parameter

英文关键词： Fano Resonance；Localized Surface Plasmon Resonance；Oligomer Cluster；Dark State；Molecular Point Group Theory