EAGER: Microstructured Sapphire Optical Fiber for SERS Sensing and Measurements at Elevated Temperatures

目的：该项目的目的是探索一种创新的概念，该概念将导致多孔阳极氧化铝作为包层的微结构蓝宝石纤维，进一步作为Au和Ag纳米粒子的锚点，用于高温下表面增强拉曼散射的化学传感和测量。智力优势：智力优势是理论上计算多孔氧化铝包层中的模式场分布，以确定高模式场重叠和强光分析物相互作用的氧化物的最佳微观结构；以计算结果为指导，在蓝宝石纤维上涂覆和阳极氧化Al涂层，得到多孔氧化包覆的微结构蓝宝石纤维；并评估用银和金纳米粒子修饰的微结构蓝宝石纤维在500º-1500ºC热燃烧气体中进行SERS测量的可行性。该项目具有变革性，因为它将帮助引入一种新的特种光纤类别，用于现有光纤技术不适合的苛刻应用。更广泛影响：更广泛的影响是多方面的。从技术上讲，光耦合微结构蓝宝石纤维可以用作微反应器或试验台，用于开发和理解新的催化现象，激光光谱作为一种强大的原位探测技术。从教育的角度来看，这个项目将为研究生和不同群体的本科生和高中生提供肥沃的训练场地。与捷克研究人员的合作增加了一个重要的国际层面。研究成果的传播将通过会议报告和同行评议的出版物来实现。

Objective: The objective of this program is to explore an innovative concept that leads to microstructured sapphire fibers with porous, anodized aluminum oxide as cladding that further functions as anchor of Au and Ag nanoparticles for chemical sensing and measurements by surface-enhanced Raman scattering at high temperatures. Intellectual Merit: The intellectual merit is to theoretically calculate mode-field distribution in the porous aluminum oxide cladding to determine the optimal microstructure of the oxide for high mode-field overlap and thus strong light-analyte interactions; to use the calculated results as a guide to coat and anodize Al coating on sapphire fiber to obtain porous oxide-cladded microstructured sapphire fiber; and to evaluate the feasibility of microstructured sapphire fibers decorated with Ag and Au nanoparticles for SERS measurements of hot combustion gas at 500º-1500ºC. The program is transformative in that it will help usher in a new category of specialty optical fibers for demanding applications where existing fiber technologies are not suitable.Broader Impacts: The broader impacts are multi-faceted. Technologically speaking, optically coupled microstructured sapphire fibers could be used as a micro-reactor or test bed for the development and understanding of new catalytic phenomena with laser spectroscopy as a powerful in-situ probing technique. From educational perspective, this program will provide a fertile training ground for a graduate student and a diverse group of undergraduate and high school students. The collaboration with Czech researchers adds a significant international dimension. Dissemination of research results will be achieved via conference presentations and peer-reviewed publications.