Collaborative Research: Metasurface-Enabled Broadband Circular Dichroism Spectroscopy and Imaging

在化学系化学测量和成像计划的支持下，耶鲁大学的郭培军及其团队和宾夕法尼亚州立大学的倪兴杰及其团队正在合作推进手性分子(即显示惯用手的分子)和材料的表征。圆二色谱(CD)是一种可以用来探测分子手性的光学性质。Guo/Ni团队正在设计亚表面-可以操纵光的各种属性的结构，包括其手性-显著简化CD光谱仪，从而以显著的灵敏度和高通量促进CD光谱和成像实验。该项目为研究生和本科生提供纳米制造、光-物质相互作用以及先进光学测量设备的组装和改装领域的实践培训。此外，该项目旨在通过与耶鲁路径和宾夕法尼亚州立大学科学外展办公室合作，鼓励年轻学生进入STEM(科学、技术、工程和数学)领域，以吸引K-12学生参与研究。这个合作项目专注于为圆二色(CD)测量的新方法设计、制造和评估亚表面。超表面设计的波长范围从紫外线到太赫兹，其中的一部分目前还没有被商业CD光谱仪覆盖。几种典型的手性系统，包括手性分子、手性胶体纳米晶和手性二维杂化钙钛矿，正被用于对亚表面启用的光学工具进行基准测试。元表面本质上是衍射性的，因此它们能够进行单次激发兼容的CD表征，这使得它们对于监控不可逆转的化学过程是非常宝贵的。亚表面可用于其他光学测量技术，如磁光克尔效应和时间分辨法拉第旋转。这些技术为理解化学合成和催化、能量转换和量子信息科学提供了强大的探测器。参与这个项目的学生将获得对纳米光子学、光学光谱学和成像方法的深刻理解，为他们提供对这些快速发展的科学领域的宝贵、实用的见解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Peijun Guo and his group at Yale University and Xingjie Ni and his group at Pennsylvania State University are collaboratively advancing the characterization of chiral molecules (i.e. molecules that display handedness) and materials. Circular dichroism (CD) is an optical property that can be used to probe molecular chirality. The Guo/Ni team is engineering metasurfaces – structures that can manipulate various properties of light, including its chirality – to significantly simplify CD spectrometers, thereby facilitating CD spectroscopy and imaging experiments with remarkable sensitivity and high throughput. The project offers hands-on training to both graduate and undergraduate students in areas of nanofabrication, light-matter interactions, and the assembly and adaptation of advanced optical measurement setups. Moreover, the project aims to motivate younger students to venture into STEM (science, technology, engineering and mathematics) fields by partnering with the Yale Pathways and the Office of Science Outreach at Penn State to engage K-12 students to the research.This collaborative project focuses on the design, fabrication, and evaluation of metasurfaces for a novel approach to circular dichroism (CD) measurements. The metasurfaces are designed to span wavelengths ranging from the ultraviolet to terahertz, portions of which are presently not covered by commercial CD spectrometers. Several prototypical chiral systems, including chiral molecules, chiral colloidal nanocrystals, and chiral two-dimensional hybrid perovskites, are being used for benchmarking the metasurface-enabled optical tools. The metasurfaces are intrinsically diffractive, hence they enable single shot-compatible CD characterization, making them invaluable for monitoring irreversible chemical processes. The metasurfaces can be incorporated in other optical measurement techniques such as magneto-optic Kerr effect and time-resolved Faraday rotation. These techniques offer powerful probes for understanding chemical synthesis and catalysis, energy conversion, and quantum information science. Students involved in this project will acquire a profound understanding of nanophotonics, optical spectroscopy, and imaging methods, offering them valuable, practical insights into these rapidly evolving scientific fields.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.