OP: Super-Coupling Nanoplasmonics with Silicon Photonics for Mid-Infrared Biosensing

非技术性：该项目旨在开发一种小型化和集成的光学传感器系统，以检测具有即时应用潜力的生物医学分子。该传感器测量分子对红外光的独特光吸收特性，具有高灵敏度和识别能力。此外，该项目将实现一种由金属光学纳米结构和硅波导组成的新型结构，它们有效地耦合在一起。新架构还可能导致用于高速光通信的高效光电设备，这些设备将在未来的数据中心和5G无线网络中发挥重要作用。在教育方面，该项目将为研究生和本科生提供纳米技术和仪器方面的经验。在K-12外展方面，PI将每年在明尼苏达科学博物馆建立一个互动活动站，并提高公众对纳米技术对我们社会的好处的认识。更多的妇女和代表性不足的少数民族将有机会体验纳米技术。最后，研究员将继续支持REU和当地招募高中生进行暑期研究经验。技术：纳米等离子体和硅光子学是两类光子系统，在光的操纵和检测方面具有独特的功能和优势。以协同的方式集成这两种独特的系统可以潜在地联合收割机结合它们的优点并克服它们的缺点，以实现从化学和生物传感到光电子学和光通信的应用。然而，实现这种混合集成方法的效率和灵敏度，是由两个系统中的不同类型的光学模式之间的大的相位失配，这导致它们之间的低耦合效率阻碍。该计划旨在解决这个问题，并实现一个混合平台，有效地集成了纳米等离子体共振器和硅光子波导，重点是在技术上重要的中红外（中红外）波段的操作。通过利用环形等离子体同轴谐振器中的ε近零（ENZ）现象所带来的超耦合效应，创新性地解决了相位失配的挑战，以实现大于90%的波导-等离子体耦合效率。该混合系统能够实现表面增强红外吸收（SEIRA）传感，这将与模型系统，如脂质双层膜和蛋白质。该计划有三方面的智力优势。首先，探索并利用由ε近零（ENZ）现象实现的超耦合的新物理来有效地将纳米等离子体激元谐振器与硅波导耦合。第二个智力优势在于中红外波段的研究重点，这是目前正在经历非常快速的发展，是非常强大的光谱化学和生物传感。该计划的第三个智力价值是实现SEIRA生物传感。研究了一种新的反射模式检测方案，该方案避免了IR光通过溶液的通道，从而在很大程度上避免了水吸收。预期信噪比的显著改善将直接导致SEIRA的检测灵敏度增强。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical: This project aims to develop a miniaturized and integrated optical sensor system to detect biomedical molecules with the potential for point-of-care applications. The sensor measures the molecule's unique optical absorption features of infrared light, with high sensitivity and the capability of identifying them. Moreover, the project will realize a novel structure consisting of metallic optical nanostructures and silicon waveguide, which are efficiently coupled together. The new architecture may also lead to efficient optoelectronic devices for high-speed optical communications that will play an important role in future data centers and 5G wireless network. For education, the project will provide graduate and undergraduate students with experience in nanotechnology and instrumentation. For K-12 outreach, the PIs will build an interactive Activity Station at the Science Museum of Minnesota every year and enhance the public awareness of the benefits of nanotechnology to our society. More women and underrepresented minorities will be given opportunities to experience nanotechnology. Finally, the PIs will continue support for REU and local recruit high school students for summer research experience.Technical: Nanoplasmonics and silicon photonics are two categories of photonic systems with unique features and advantages in the manipulation and detection of light. Integrating the two distinctive systems in a synergistic way can potentially combine their merits and circumvent their weakness, to enable applications ranging from chemical and biological sensing to optoelectronics and optical communications. The realization of such a hybrid integration approach with both efficiency and sensitivity, however, is hindered by the large phase mismatching between the different types of optical modes in the two systems, which leads to low coupling efficiency between them. This program aims to solve the problem and achieve a hybrid platform that efficiently integrates nanoplasmonic resonators and silicon photonic waveguides with an emphasis on operation in the technologically important mid-infrared (mid-IR) band. The phase mismatching challenge is resolved innovatively by utilizing the super-coupling effect brought by the epsilon-near-zero (ENZ) phenomenon in ring-shaped plasmonic coaxial resonators to achieve waveguide-plasmonics coupling efficiency greater than 90%. The hybrid system enables surface-enhanced infrared absorption (SEIRA) sensing, which will be demonstrated with model systems such as lipid bilayer membranes and proteins. There are three-fold intellectual merits of the program. First, the novel physics of super-coupling enabled by the epsilon-near-zero (ENZ) phenomenon is explored and utilized to efficiently couple nanoplasmonic resonators with silicon waveguides. The second intellectual merit lies in the research emphasis in the mid-IR band, which is currently experiencing very fast development and is exceedingly powerful for spectroscopic chemical and biological sensing. The third intellectual merit of the program is to achieve SEIRA biosensing. A new reflection mode detection scheme is investigated that avoids the passage of IR light through the solution and thus largely circumvents water absorption. The anticipated significant improvement in the signal-to-noise ratio would directly lead to enhanced detection sensitivity in SEIRA.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.