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Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth
Broadband terahertz spectroscopy enables many promising applications in science and industry alike. However, the complexity of existing terahertz systems has as yet prevented the breakthrough of this technology. In particular, established terahertz time-domain spectroscopy (TDS) schemes rely on comp...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Nature Publishing Group UK
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886886/ https://www.ncbi.nlm.nih.gov/pubmed/33594078 http://dx.doi.org/10.1038/s41467-021-21260-x |
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author | Liebermeister, Lars Nellen, Simon Kohlhaas, Robert B. Lauck, Sebastian Deumer, Milan Breuer, Steffen Schell, Martin Globisch, Björn |
author_facet | Liebermeister, Lars Nellen, Simon Kohlhaas, Robert B. Lauck, Sebastian Deumer, Milan Breuer, Steffen Schell, Martin Globisch, Björn |
author_sort | Liebermeister, Lars |
collection | PubMed |
description | Broadband terahertz spectroscopy enables many promising applications in science and industry alike. However, the complexity of existing terahertz systems has as yet prevented the breakthrough of this technology. In particular, established terahertz time-domain spectroscopy (TDS) schemes rely on complex femtosecond lasers and optical delay lines. Here, we present a method for optoelectronic, frequency-modulated continuous-wave (FMCW) terahertz sensing, which is a powerful tool for broadband spectroscopy and industrial non-destructive testing. In our method, a frequency-swept optical beat signal generates the terahertz field, which is then coherently detected by photomixing, employing a time-delayed copy of the same beat signal. Consequently, the receiver current is inherently phase-modulated without additional modulator. Owing to this technique, our broadband terahertz spectrometer performs (200 Hz measurement rate, or 4 THz bandwidth and 117 dB peak dynamic range with averaging) comparably to state-of-the-art terahertz-TDS systems, yet with significantly reduced complexity. Thickness measurements of multilayer dielectric samples with layer-thicknesses down to 23 µm show its potential for real-world applications. Within only 0.2 s measurement time, an uncertainty of less than 2 % is achieved, the highest accuracy reported with continuous-wave terahertz spectroscopy. Hence, the optoelectronic FMCW approach paves the way towards broadband and compact terahertz spectrometers that combine fiber optics and photonic integration technologies. |
format | Online Article Text |
id | pubmed-7886886 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-78868862021-03-03 Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth Liebermeister, Lars Nellen, Simon Kohlhaas, Robert B. Lauck, Sebastian Deumer, Milan Breuer, Steffen Schell, Martin Globisch, Björn Nat Commun Article Broadband terahertz spectroscopy enables many promising applications in science and industry alike. However, the complexity of existing terahertz systems has as yet prevented the breakthrough of this technology. In particular, established terahertz time-domain spectroscopy (TDS) schemes rely on complex femtosecond lasers and optical delay lines. Here, we present a method for optoelectronic, frequency-modulated continuous-wave (FMCW) terahertz sensing, which is a powerful tool for broadband spectroscopy and industrial non-destructive testing. In our method, a frequency-swept optical beat signal generates the terahertz field, which is then coherently detected by photomixing, employing a time-delayed copy of the same beat signal. Consequently, the receiver current is inherently phase-modulated without additional modulator. Owing to this technique, our broadband terahertz spectrometer performs (200 Hz measurement rate, or 4 THz bandwidth and 117 dB peak dynamic range with averaging) comparably to state-of-the-art terahertz-TDS systems, yet with significantly reduced complexity. Thickness measurements of multilayer dielectric samples with layer-thicknesses down to 23 µm show its potential for real-world applications. Within only 0.2 s measurement time, an uncertainty of less than 2 % is achieved, the highest accuracy reported with continuous-wave terahertz spectroscopy. Hence, the optoelectronic FMCW approach paves the way towards broadband and compact terahertz spectrometers that combine fiber optics and photonic integration technologies. Nature Publishing Group UK 2021-02-16 /pmc/articles/PMC7886886/ /pubmed/33594078 http://dx.doi.org/10.1038/s41467-021-21260-x Text en © The Author(s) 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Liebermeister, Lars Nellen, Simon Kohlhaas, Robert B. Lauck, Sebastian Deumer, Milan Breuer, Steffen Schell, Martin Globisch, Björn Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth |
title | Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth |
title_full | Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth |
title_fullStr | Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth |
title_full_unstemmed | Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth |
title_short | Optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 THz bandwidth |
title_sort | optoelectronic frequency-modulated continuous-wave terahertz spectroscopy with 4 thz bandwidth |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886886/ https://www.ncbi.nlm.nih.gov/pubmed/33594078 http://dx.doi.org/10.1038/s41467-021-21260-x |
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