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Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification
Stand‐off Raman spectroscopy offers a highly selective technique to probe unknown substances from a safe distance. Often, it is necessary to scan large areas of interest. This can be done by pointwise imaging (PI), that is, spectra are sequentially acquired from an array of points over the region of...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6774338/ https://www.ncbi.nlm.nih.gov/pubmed/31598032 http://dx.doi.org/10.1002/jrs.5607 |
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author | Gasser, Christoph González‐Cabrera, María Ayora‐Cañada, María José Domínguez‐Vidal, Ana Lendl, Bernhard |
author_facet | Gasser, Christoph González‐Cabrera, María Ayora‐Cañada, María José Domínguez‐Vidal, Ana Lendl, Bernhard |
author_sort | Gasser, Christoph |
collection | PubMed |
description | Stand‐off Raman spectroscopy offers a highly selective technique to probe unknown substances from a safe distance. Often, it is necessary to scan large areas of interest. This can be done by pointwise imaging (PI), that is, spectra are sequentially acquired from an array of points over the region of interest (point‐by‐point mapping). Alternatively, in this paper a direct hyperspectral Raman imager is presented, where a defocused laser beam illuminates a wide area of the sample and the Raman scattered light is collected from the whole field of view (FOV) at once as a spectral snapshot filtered by a liquid crystal tunable filter to select a specific Raman shift. Both techniques are compared in terms of achievable FOV, spectral resolution, signal‐to‐noise performance, and time consumption during a measurement at stand‐off distance of 15 m. The HSRI showed superior spectral resolution and signal‐to‐noise ratio, while more than doubling the FOV of the PI at laser power densities reduced by a factor of 277 at the target. Further, the output hyperspectral image data cube can be processed with state of the art chemometric algorithms like vertex component analysis in order to get a simple deterministic false color image showing the chemical composition of the target. This is shown for an artificial polymer sample, measured at a distance of 15 m. |
format | Online Article Text |
id | pubmed-6774338 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-67743382019-10-07 Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification Gasser, Christoph González‐Cabrera, María Ayora‐Cañada, María José Domínguez‐Vidal, Ana Lendl, Bernhard J Raman Spectrosc Research Articles Stand‐off Raman spectroscopy offers a highly selective technique to probe unknown substances from a safe distance. Often, it is necessary to scan large areas of interest. This can be done by pointwise imaging (PI), that is, spectra are sequentially acquired from an array of points over the region of interest (point‐by‐point mapping). Alternatively, in this paper a direct hyperspectral Raman imager is presented, where a defocused laser beam illuminates a wide area of the sample and the Raman scattered light is collected from the whole field of view (FOV) at once as a spectral snapshot filtered by a liquid crystal tunable filter to select a specific Raman shift. Both techniques are compared in terms of achievable FOV, spectral resolution, signal‐to‐noise performance, and time consumption during a measurement at stand‐off distance of 15 m. The HSRI showed superior spectral resolution and signal‐to‐noise ratio, while more than doubling the FOV of the PI at laser power densities reduced by a factor of 277 at the target. Further, the output hyperspectral image data cube can be processed with state of the art chemometric algorithms like vertex component analysis in order to get a simple deterministic false color image showing the chemical composition of the target. This is shown for an artificial polymer sample, measured at a distance of 15 m. John Wiley and Sons Inc. 2019-04-30 2019-07 /pmc/articles/PMC6774338/ /pubmed/31598032 http://dx.doi.org/10.1002/jrs.5607 Text en © 2019 The Authors Journal of Raman Spectroscopy Published by John Wiley & Sons Ltd This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Articles Gasser, Christoph González‐Cabrera, María Ayora‐Cañada, María José Domínguez‐Vidal, Ana Lendl, Bernhard Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification |
title | Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification |
title_full | Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification |
title_fullStr | Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification |
title_full_unstemmed | Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification |
title_short | Comparing mapping and direct hyperspectral imaging in stand‐off Raman spectroscopy for remote material identification |
title_sort | comparing mapping and direct hyperspectral imaging in stand‐off raman spectroscopy for remote material identification |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6774338/ https://www.ncbi.nlm.nih.gov/pubmed/31598032 http://dx.doi.org/10.1002/jrs.5607 |
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