Instrument Development: A Miniature, High-resolution, Stationary Grating Spatial Heterodyne UV Raman Spectrometer-Towards Miniature UV Raman Sensors and "Raman on a Chip"

在化学系化学测量和成像项目的支持下，斯坦利·M·安吉尔教授和他在南卡罗来纳大学的学生们将开发出体积空前小的微型深紫外拉曼光谱仪。小型化拉曼光谱仪的设计基于静止光栅、空间外差光谱仪(SHS)，将具有高光谱分辨率、大光谱范围和高光通量。建议的紫外拉曼光谱仪是一种全新的设计，允许毫米尺寸的光谱仪具有与更大的仪器相当或更好的光谱特性，并且比同等尺寸的传统拉曼仪器具有更高的光吞吐量，并且具有高接受角。这项拟议的工作旨在向微型拉曼化学传感器迈进。该光谱仪将极大地扩大拉曼光谱在广泛的应用中用于在线、原位、在体和距离测量的适用性。该项目将包括四个主要领域的研究：1)基于SHS的拉曼光谱仪的基本尺寸限制是什么，2)噪声和背景源如何随仪器尺寸的变化而变化，3)干涉仪输出如何与外部探测器耦合，以及4)微型紫外拉曼光谱仪的问世带来了哪些新的应用。将探讨在线光谱传感器对化学过程监测以及先进和添加剂制造的影响。拉曼光谱仪通过记录样品中分子振动产生的入射光波长(颜色)的微小变化来提供有关样品分子组成的信息。在这个项目中，微型光谱工具将使用尖端技术开发，开辟了分析测量的全新领域，因为所提出的微型SHRS的小尺寸和UV光谱性能将大大拓宽拉曼光谱仪的应用范围。潜在的应用领域包括化学过程监测、在线化学动力学测量、生物组织和细胞成像、对峙取证分析、行星探测、手持地质仪器、深海海洋测量、电子设备表征、烈性爆炸物探测等。该项目还为本科生和研究生提供了获取光谱学、激光和光学以及分析化学应用方面的知识和技能的绝佳机会。

With support from the Chemical Measurement and Imaging program in the Division of Chemistry, Prof. Stanley M. Angel and his students at the University of South Carolina, will develop miniature deep-UV Raman spectrometers of unprecedentedly small size. The miniature Raman spectrometer design is based on a stationary grating, spatial heterodyne spectrometer (SHS) and will have high spectral resolution, a large spectral range and high light throughput. The proposed UV Raman spectrometer is a radically new design that allows mm-size spectrometers with spectral characteristics equal to or better than larger instruments and with higher light throughput than conventional Raman instruments of comparable size, and with high acceptance angle. The proposed work is designed to move towards miniature Raman chemical sensors. The spectrometer will substantially broaden the applicability of Raman for on-line, in-situ, in-vivo, and standoff measurements, in wide-ranging applications. This project will include studies in four major areas: 1) what are the fundamental size limitations of a SHS based Raman spectrometer, 2) how do noise and background sources scale with instrument size, 3) how can an interferometer output be coupled to an external detector, and 4) what new applications are made possible by the availability of a miniature UV Raman spectrometer. The implications of on-line spectroscopic sensors to chemical process monitoring and advanced and additive manufacturing will be explored. Raman spectrometers provide information about the molecular composition of samples by recording small changes in the wavelength (color) of incident light produced by molecular vibrations in the sample. In this project, miniature spectroscopic tools will be developed using cutting-edge technology, opening up whole new areas of analytical measurement possibilities because the small size and UV spectroscopic performance of the miniature SHRS proposed will substantially broaden the range of Raman spectrometer applications. Areas of potential use include chemical process monitoring, on-line chemical kinetics measurements, imaging of biological tissues and cells, standoff forensics analysis, planetary exploration, hand held geological instruments, deep-ocean oceanographic measurements, electronics device characterization, high explosives detection, and many others. This project also provides outstanding opportunities for undergraduates and graduate students to acquire knowledge and skills in spectroscopy, lasers and optics as well as applications of analytical chemistry.