GOALI: Nanostructured Sapphire Optical Fiber for Sensing in Harsh Environment

非技术描述：蓝宝石光纤在恶劣环境中传感的优异潜力，如在先进的基于燃烧的能源发电系统中遇到的高运行效率和低排放，早已得到认可。在蓝宝石光纤上缺乏可用于低损耗光传输和光纤保护的可行包层仍然是实际应用的障碍。该项目旨在开发一种在蓝宝石纤维上具有高度组织的纳米级空气通道的新型氧化铝包层，并通过铝纤维涂层和阳极氧化的策略，了解相关的工艺-结构-性能-性能相关性，以实现倏逝场化学传感和测量。该项目的成功有可能克服长达数十年的蓝宝石光纤包层挑战，并为蓝宝石光纤技术的变革提供无数机会，特别是在硅光纤传感器不再适用的不利条件下进行传感。该项目是由史蒂文斯理工学院和Fiberguide工业公司合作进行的。技术细节：无法制造稳定和高质量的受控光学特性包层严重阻碍了蓝宝石光纤传感器的设计和开发，特别是在高温腐蚀环境中。本项目旨在开发和评估蓝宝石纤维纳米结构氧化铝包层，用于倏逝场化学传感和测量。主要目标是：(1)评价模场重叠与包层纳米结构之间的理论相关性，以指导包层的制备；(2)在Fiberguide确定铝涂层和阳极氧化的工艺参数窗口以及放大；(3)利用倏逝场激光吸收和表面增强拉曼散射作为检测模式，建立和理解包层纳米结构与燃烧环境下传感性能之间的相互作用。该项目具有变革性，因为它有可能解决蓝宝石光纤长期面临的瓶颈包层问题，并且由此产生的特种光纤很可能导致蓝宝石光纤技术的重大发展。此外，产业伙伴关系和国际合作作为研究活动的一个组成部分，极大地丰富了参与该项目的博士、本科和高中学者的教育和研究培训经验。

NON-TECHNICAL DESCRIPTION: The excellent potential of sapphire optical fiber for sensing in harsh environments such as those encountered in advanced combustion-based energy generation systems for high operation efficiency and low emission has long been recognized. The lack of viable cladding on sapphire fiber for low-loss light transmission and fiber protection remains the roadblock to real-world applications. This project aims to develop a novel alumina cladding with highly organized nano-sized air channels on sapphire fiber and to understand the associated processing-structure-property-performance correlations for evanescent-field chemical sensing and measurements via a strategy of fiber coating with aluminum followed by its anodization. The success of the project has the potential to overcome the decades-old sapphire fiber cladding challenge as well as offer a myriad of opportunities to transformative sapphire fiber-optic technology especially for sensing under adverse conditions where silica fiber sensors are no longer suitable. This project is carried out in partnership between Stevens Institute of Technology and Fiberguide Industries, Inc. TECHNICAL DETAILS: The inability to fabricate stable and high-quality cladding of controlled optical properties severely hampers the design and development of sapphire fiber sensors for a host of applications, particularly in corrosive environments at high temperatures. This project aims to develop and evaluate nanostructured alumina cladding on sapphire fiber for evanescent-field chemical sensing and measurements. The main objectives are: (1) evaluation of the theoretical correlation between mode-field overlap and cladding nanostructure to guide cladding fabrication; (2) determination of the window of processing parameters for aluminum coating and anodization as well as scale-up at Fiberguide; and (3) establishment and understanding of the interplay between the cladding nanostructure and sensing performance in combustion environment using evanescent-field laser absorption and surface-enhanced Raman scattering as the detection modalities. This project is transformative in that it has the potential to resolve the bottle-neck cladding problem long-faced by sapphire fiber and that the resultant specialty optical fiber may well lead to significant development of sapphire fiber-optic technology. Furthermore, industrial partnership and international collaboration as an integral part of the research activities greatly enriches the educational and research training experiences of the doctoral, undergraduate and high-school scholars participating in this project.