高耦合强聚焦表面等离激元探针的设计研制与高空间分辨表征

项目名称： 高耦合强聚焦表面等离激元探针的设计研制与高空间分辨表征

项目编号： No.61505251

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 张明倩

作者单位： 中国空间技术研究院

项目金额： 20万元

中文摘要： 探针增强近场光学显微术是纳米器件与材料光学特性超分辨表征的重要手段。当前，该技术研究多局限于空间光场与探针尖端的直接耦合增强，致使耦合效率较低、局域增强不足、远场背景噪声强，限制了其在纳米光场微弱信号探测中的应用。本课题旨在将等离激元结构与探针结合，研制一种高耦合强聚焦表面等离激元探针，有效提升探针增强近场光学显微镜的性能。采取的思路是：利用等离激元结构的波矢匹配，获得表面等离激元波的高效激发耦合；基于光场调控作用，使其向探针尖端低损耗定向传播；通过探针结构的相位匹配，在针尖尖端形成局域聚焦增强纳米光场。我们将开展该新型探针的数值模拟设计及其光学响应特性的高空间分辨率表征和光学性能的实验研究，优化表面等离激元探针的设计结构和参数，最终实现具有高效入射光耦合能力和强烈局域电磁场增强作用的表面等离激元探针的研制。为探针增强光谱术、局域等离激元探测、超分辨成像等研究提供重要的理论和关键技术基础。

中文关键词： 近场光学；表面等离激元；局域电磁场增强；探针增强；纳米光场探测

英文摘要： Tip-enhanced near-field optical microscopy is an important method for optical properties characterization of the nano-devices and nano-materials with super-resolution. Nowadays, researches are mostly focused on the direct coupling of the incident light with the tip apex. As a result, the coupling efficiency is relatively low, the local field enhancement is insufficient, and the far-field background noise is rather strong. And these difficulties limit its application in the weak signal detection of the nano-optical field. In this research, we prose to combine the plasmonic structure with the tip, and design a novel plasmonic probe with plasmonic structures fabricated on the shaft or top of the probe to provide the tip with efficient optical field excitation and regulation abilities. Hence, the plasmonic probe is capable of producing extremely strong locally enhanced nano-optical field. The enhancement process owns to the joint effect of surface plasmon and localized surface plasmon effects, resulting in effectively advanced enhancement. Therefore, the local field enhancement and the detection sensitivity of the nano-optical field characterization are significantly improved, based on the field enhancement of the plasmonic probe. In this research, the mechanism of the interaction between the incident optical field and the plasmonic probe will be investigated. The design method of a plasmonic probe will be studied and established. Then the optical responses of a plasmonic probe will be experimentally characterized with near-field optical method. The efficient coupling of the optical field and localized field enhancement based on a plasmonic porbe will be achieved. It will provide theoretical foundation and technical exploration for the development of the tip-enhanced nano-optical field detection method, and effectively advance the characterization techniques of nano-optical field and the nanomaterial’s optical properties.

英文关键词： near-field optics ;surface plasmon polariton;local electromagnetic field enhancement;tip-enhancement;nano-optical field detection