Outdoor Measurements of Leaf Water Content Using THz Quasi Time-Domain Spectroscopy
- 39 Downloads
We report the first outdoor measurements for continuous in vivo leaf-water monitoring using THz spectroscopy. For this, we have developed a compact and portable THz quasi time-domain spectrometer which can be powered by a battery. We monitor the water status of a corn plant (Zea mays) and discuss the influence of the day-night variations of the outdoor temperature.
KeywordsTHz QTDS Leaf water
- 1.D.M. Mittleman, R.H. Jacobsen, and M.C. Nuss, T-ray imaging, IEEE Journal of Selected Topics in Quantum Electronics 2 (1996), no. 3, 679–692.Google Scholar
- 2.M. Koch, Bio-medical applications of thz imaging. In: Mittleman, D. (ed.) Sensing with Terahertz Radiation: Springer (2003) pp. 295–316.Google Scholar
- 3.E. Castro-Camus, M. Palomar, and A.A. Covarrubias, Leaf water dynamics of arabidopsis thaliana monitored in-vivo using terahertz time-domain spectroscopy, Scientific reports 3 (2013), 1–5.Google Scholar
- 4.N. Born, D. Behringer, S. Liepelt, S. Beyer, M. Schwerdtfeger, B. Ziegenhagen, and M. Koch, Monitoring plant drought stress response using terahertz time-domain spectroscopy, Plant Physiology 164 (2014), no. 4, 1571–1577.Google Scholar
- 5.R. Gente and M. Koch, Monitoring leaf water content with THz and sub-THz waves, Plant Methods 11 (2015), no. 1, 1–9.Google Scholar
- 6.L. Baldacci, M. Pagano, L. Masini, A. Toncelli, G. Carelli, P. Storchi, and A. Tredicucci, Non-invasive absolute measurement of leaf water content using terahertz quantum cascade lasers, Plant Methods 13 (2017), no. 1, 51.Google Scholar
- 7.M. Tani, S. Matsuura, K. Sakai, and M. Hangyo, Multiple-frequency generation of sub-terahertz radiation by multimode ld excitation of photoconductive antenna, IEEE Microw. Guided Wave Lett. 7 (1997), no. 9, 282–284.Google Scholar
- 8.M. Scheller and M. Koch, Terahertz quasi time domain spectroscopy, Opt Express 17 (2009), no. 20, 17723–17733.Google Scholar
- 9.T. Probst, A. Rehn, and M. Koch, Compact and low-cost THz QTDS system, Optics express 23 (2015), no. 17, 21972–21982.Google Scholar
- 10.R.B. Kohlhaas, A. Rehn, S. Nellen, M. Koch, M. Schell, R.J.B. Dietz, and J.C. Balzer, Terahertz quasi time-domain spectroscopy based on telecom technology for 1550 nm, Opt. Express 25 (2017), no. 11, 12851–12859.Google Scholar
- 11.F. Janowiak and A. Markowski, Changes in leaf water relations and injuries in maize seedlings induced by different chilling conditions, Journal of Agronomy and Crop Science 172 (1994), no. 1, 19–28.Google Scholar
- 12.H.J. Liebe, G.A. Hufford, and T. Manabe, A model for the complex permittivity of water at frequencies below 1 THz, International Journal of Infrared and Millimeter Waves 12 (1991), no. 7, 659–675.Google Scholar
- 13.C. Jördens, M. Scheller, B. Breitenstein, D. Selmar, and M. Koch, Evaluation of leaf water status by means of permittivity at terahertz frequencies, Journal of Biological Physics 35 (2009), no. 3, 255–264. https://doi.org/10.1007/s10867-009-9161-0.
- 14.R. Gente, N. Born, N. Voß, W. Sannemann, J. Léon, M. Koch, and E. Castro-Camus, Determination of leaf water content from terahertz time-domain spectroscopic data, Journal of Infrared, Millimeter, and Terahertz Waves 34 (2013), no. 3-4, 316–323. https://doi.org/10.1007/s10762-013-9972-8.
- 15.Deutscher Wetterdienst: ftp://ftp-cdc.dwd.de/pub/ (station 3164, days: 7.-9.7.2016).