微纳光纤谐振腔耦合的单纳米棒表面等离激元共振传感器研究

项目名称： 微纳光纤谐振腔耦合的单纳米棒表面等离激元共振传感器研究

项目编号： No.61475136

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 郭欣

作者单位： 浙江大学

项目金额： 80万元

中文摘要： 金属纳米棒因其超强光场约束能力和局域场增强等特性在高灵敏度生物化学传感中具有潜在的应用前景，基于金属纳米棒表面等离激元共振（SPR）的传感技术已经成为纳米光子学与传感领域的前沿研究热点之一。目前金属纳米棒SPR传感器主要依靠透镜聚焦、棱镜耦合等方式激发，激发效率低、背景噪声大，且金属材料本征吸收和颗粒散射损耗使得SPR共振峰线宽较宽，限制了传感器的灵敏度和探测极限。本项目提出利用单个金属纳米棒与微纳光纤谐振腔耦合实现单分子灵敏度传感的研究设想。通过微纳光纤导模高效率耦合激发光纤表面单纳米棒SPR，利用微纳光纤环形谐振腔与金属纳米棒SPR的耦合，显著压缩SPR共振线宽，提高光谱检测分辨率，实现单分子灵敏度、无需标记、低噪声、低功耗的光学传感。研究结果对于SPR传感新机理和新技术的研究以及高灵敏度生物化学传感器在生物医学、环境检测、食品安全等方面的应用将具有重要意义。

中文关键词： 微纳光纤；表面等离激元共振；金属纳米棒；谐振腔；光学传感

英文摘要： Owing to their merits such as tight confinement, localized electromagnetic field enhancement, metal nanorods have shown promising applications in high-sensitive chemical or biological sensing, and the study of metal-nanorod-mediated surface plasmon resonance (SPR) sensors has been an attractive subject in the fields of nanophotonics and optical sensing. To date, the excitation of metal nanorods mainly relies on methods such as lens focusing or prism coupling, resulting in low photon-to-plasmon conversion efficiency and large background noise. Moreover, metal nanorods usually suffer from high losses due to metal's intrinsic absorption and nanoparticles' radiative scattering, which significantly broaden the plasmonic resonance linewidths of single nanorods, and severely deteriorate the sensing sensitivity and detection limit. With this regard, we propose to realize single molecule sensors based on the coupling of single metal nanorod and micro-/nanofiber resonator. The SPR in single metal nanorods, which are deposited on the surface of optical micro-/nanofibers, can be evanescently excited with high efficiency. Based on the near-field interaction between resonant modes of micro-/nanofiber ring resonators and SPR modes of single nanorods, we will study the reduction in plasmonic resonance linewidth of single nanorods and realize label-free optical sensors with single molecule sensitivity, low noise and low power consumption. We believe that the results may be of great importance to the investigation of new mechanism and technology of SPR sensors, as well as the development of high-sensitive biological or chemical sensors in future applications such as biomedicine, environment detection and food safety.

英文关键词： Optical micro-/nanofibers;surface plasmon resonance;metal nanorods;resonators;optical sensing