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Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing
Terahertz waves are located in the frequency band between radio waves and light, and they are being considered for various applications as a light source. Generally, the use of light requires focusing; however, when a terahertz wave is irradiated onto a small detector or a small measurement sample,...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7922924/ https://www.ncbi.nlm.nih.gov/pubmed/33670649 http://dx.doi.org/10.3390/s21041419 |
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author | Sugaya, Toshio Kawano, Yukio |
author_facet | Sugaya, Toshio Kawano, Yukio |
author_sort | Sugaya, Toshio |
collection | PubMed |
description | Terahertz waves are located in the frequency band between radio waves and light, and they are being considered for various applications as a light source. Generally, the use of light requires focusing; however, when a terahertz wave is irradiated onto a small detector or a small measurement sample, its wavelength, which is much longer than that of visible light, causes problems. The diffraction limit may make it impossible to focus the terahertz light down to the desired range by using common lenses. The Bull’s Eye structure, which is a plasmonic structure, is a promising tool for focusing the terahertz light beyond the diffraction limit and into the sub-wavelength region. By utilizing the surface plasmon propagation, the electric field intensity and transmission coefficient can be enhanced. In this study, we improved the electric field intensity and light focusing in a small region by adapting the solid immersion method (SIM) from our previous study, which had a frequency-tunable nonconcentric Bull’s Eye structure. Through electromagnetic field analysis, the electric field intensity was confirmed to be approximately 20 times higher than that of the case without the SIM, and the transmission measurements confirmed that the transmission through an aperture had a gap of 1/20 that of the wavelength. This fabricated device can be used in imaging and sensing applications because of the close contact between the transmission aperture and the measurement sample. |
format | Online Article Text |
id | pubmed-7922924 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-79229242021-03-03 Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing Sugaya, Toshio Kawano, Yukio Sensors (Basel) Communication Terahertz waves are located in the frequency band between radio waves and light, and they are being considered for various applications as a light source. Generally, the use of light requires focusing; however, when a terahertz wave is irradiated onto a small detector or a small measurement sample, its wavelength, which is much longer than that of visible light, causes problems. The diffraction limit may make it impossible to focus the terahertz light down to the desired range by using common lenses. The Bull’s Eye structure, which is a plasmonic structure, is a promising tool for focusing the terahertz light beyond the diffraction limit and into the sub-wavelength region. By utilizing the surface plasmon propagation, the electric field intensity and transmission coefficient can be enhanced. In this study, we improved the electric field intensity and light focusing in a small region by adapting the solid immersion method (SIM) from our previous study, which had a frequency-tunable nonconcentric Bull’s Eye structure. Through electromagnetic field analysis, the electric field intensity was confirmed to be approximately 20 times higher than that of the case without the SIM, and the transmission measurements confirmed that the transmission through an aperture had a gap of 1/20 that of the wavelength. This fabricated device can be used in imaging and sensing applications because of the close contact between the transmission aperture and the measurement sample. MDPI 2021-02-18 /pmc/articles/PMC7922924/ /pubmed/33670649 http://dx.doi.org/10.3390/s21041419 Text en © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Communication Sugaya, Toshio Kawano, Yukio Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing |
title | Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing |
title_full | Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing |
title_fullStr | Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing |
title_full_unstemmed | Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing |
title_short | Frequency-Tunable Terahertz Plasmonic Structure Based on the Solid Immersed Method for Sensing |
title_sort | frequency-tunable terahertz plasmonic structure based on the solid immersed method for sensing |
topic | Communication |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7922924/ https://www.ncbi.nlm.nih.gov/pubmed/33670649 http://dx.doi.org/10.3390/s21041419 |
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