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Proceedings Paper

Long distance THz pulses propagation in the atmosphere and applications of outdoor gas sensing (Conference Presentation)
Author(s): Tae-In Jeon

Paper Abstract

In recent times, we have been studies of broadband coherent THz pulse propagation in a 186-m and 910-m open path under atmospheric weather conditions, which provides information for important applications in the atmosphere. The complexity of the atmosphere requires the use of the complete theory of Essen and Froome to compare the measured time shifts due to both the dry atmosphere and water vapor with theoretical calculations. A new procedure involving the measurement of phase in the frequency domain is introduced and achieves comparable results for the calculated time shifts, compared to the previous direct measurements of time shifts. Meanwhile, the characteristics of the N2O and CO gases are investigated using 2-m long gas chamber which is located 93m away from a THz transmitter and receiver chips. The THz pulse propagates an outside environment of 79 m between two buildings. The natural resonances of the gases are detected in the 0.5 THz bandwidth. Because the resonance spacing between two resonances of N2O gas is 0.025 THz, 14 resonances are detected in the bandwidth. However, only 3 resonances of CO gas are detected in the bandwidth. Unfortunately since the first and third resonances are too small and too close to water resonance, only the second resonance, which is at 0.35 THz, can be used to CO gas sensing frequency. Therefore, the resonances near 0.35 THz can be used to remote gas sensing window for CO and N2O gases.

Paper Details

Date Published: 5 March 2019
Proc. SPIE 10917, Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XII, 109170M (5 March 2019); doi: 10.1117/12.2516887
Show Author Affiliations
Tae-In Jeon, Korea Maritime and Ocean Univ. (Korea, Republic of)

Published in SPIE Proceedings Vol. 10917:
Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XII
Laurence P. Sadwick; Tianxin Yang, Editor(s)

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