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An effective method for substance detection using the broad spectrum THz signal with a "terahertz nose".

Trofimov VA, Varentsova SA - Sensors (Basel) (2015)

Bottom Line: We propose an effective method for the detection and identification of dangerous substances by using the broadband THz pulse.Comparing the absorption and emission spectrum dynamics of a substance under analysis with the corresponding data for a standard substance, one can detect and identify the substance under real conditions taking into account the influence of packing material, water vapor and substance surface.Restrictions of usually used detection and identification methods, based on a comparison between the absorption frequencies of a substance under analysis and a standard substance, are demonstrated using a physical experiment with paper napkins.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Leninskiye Gory, Moscow 119992, Russia;. vatro@cs.msu.ru.

ABSTRACT
We propose an effective method for the detection and identification of dangerous substances by using the broadband THz pulse. This pulse excites, for example, many vibrational or rotational energy levels of molecules simultaneously. By analyzing the time-dependent spectrum of the THz pulse transmitted through or reflected from a substance, we follow the average response spectrum dynamics. Comparing the absorption and emission spectrum dynamics of a substance under analysis with the corresponding data for a standard substance, one can detect and identify the substance under real conditions taking into account the influence of packing material, water vapor and substance surface. For quality assessment of the standard substance detection in the signal under analysis, we propose time-dependent integral correlation criteria. Restrictions of usually used detection and identification methods, based on a comparison between the absorption frequencies of a substance under analysis and a standard substance, are demonstrated using a physical experiment with paper napkins.

No MeSH data available.


Related in: MedlinePlus

Setup for the experiment for measuring THz signals at long distance [33].
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sensors-15-12103-f001: Setup for the experiment for measuring THz signals at long distance [33].

Mentions: For the TDS measurement of a neutral substance (paper layers) we exploited a THz spectrometer developed by the Teravil Company (Vilnius, Lithuania). It can operate in both transmission and reflection modes. The spectral range of the spectrometer is 0.1–5.0 THz. To provide for measurements at long distance, an additional part was developed. The experimental setup is shown in Figure 1. We use a parabolic mirror focusing the THz beam on the object. Because the fiber femtosecond laser has average power of about 1 W and the laser beam is split many times, we use an additional flat mirror behind the object. Therefore, our setup operates simultaneously in reflection-transmission mode.


An effective method for substance detection using the broad spectrum THz signal with a "terahertz nose".

Trofimov VA, Varentsova SA - Sensors (Basel) (2015)

Setup for the experiment for measuring THz signals at long distance [33].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507671&req=5

sensors-15-12103-f001: Setup for the experiment for measuring THz signals at long distance [33].
Mentions: For the TDS measurement of a neutral substance (paper layers) we exploited a THz spectrometer developed by the Teravil Company (Vilnius, Lithuania). It can operate in both transmission and reflection modes. The spectral range of the spectrometer is 0.1–5.0 THz. To provide for measurements at long distance, an additional part was developed. The experimental setup is shown in Figure 1. We use a parabolic mirror focusing the THz beam on the object. Because the fiber femtosecond laser has average power of about 1 W and the laser beam is split many times, we use an additional flat mirror behind the object. Therefore, our setup operates simultaneously in reflection-transmission mode.

Bottom Line: We propose an effective method for the detection and identification of dangerous substances by using the broadband THz pulse.Comparing the absorption and emission spectrum dynamics of a substance under analysis with the corresponding data for a standard substance, one can detect and identify the substance under real conditions taking into account the influence of packing material, water vapor and substance surface.Restrictions of usually used detection and identification methods, based on a comparison between the absorption frequencies of a substance under analysis and a standard substance, are demonstrated using a physical experiment with paper napkins.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Leninskiye Gory, Moscow 119992, Russia;. vatro@cs.msu.ru.

ABSTRACT
We propose an effective method for the detection and identification of dangerous substances by using the broadband THz pulse. This pulse excites, for example, many vibrational or rotational energy levels of molecules simultaneously. By analyzing the time-dependent spectrum of the THz pulse transmitted through or reflected from a substance, we follow the average response spectrum dynamics. Comparing the absorption and emission spectrum dynamics of a substance under analysis with the corresponding data for a standard substance, one can detect and identify the substance under real conditions taking into account the influence of packing material, water vapor and substance surface. For quality assessment of the standard substance detection in the signal under analysis, we propose time-dependent integral correlation criteria. Restrictions of usually used detection and identification methods, based on a comparison between the absorption frequencies of a substance under analysis and a standard substance, are demonstrated using a physical experiment with paper napkins.

No MeSH data available.


Related in: MedlinePlus