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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 16, Iss. 12 — Jun. 9, 2008
  • pp: 9060–9066

Diagnosing water content in paper by terahertz radiation

D. Banerjee, W. von Spiegel, M. D. Thomson, S. Schabel, and H. G. Roskos  »View Author Affiliations

Optics Express, Vol. 16, Issue 12, pp. 9060-9066 (2008)

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We explore the application of terahertz spectroscopic techniques for the remote determination of the water content of paper. The aim is the development of a rapid diagnostic imaging tool applicable in paper fabrication processes. THz radiation offers a high sensitivity for water, a good spatial resolution, and insensitivity to scattering at the paper surface. The advent of THz cameras makes fast large-area image detectors feasible. In this paper, we show for the case of a 0.6-THz fixed-frequency system, that the water content of paper can be determined with high accuracy. We demonstrate a quantitative (calibrated) method for determining the moisture content in paper based on extinction and phase measurements in the lower THz range with a spatial resolution in the mm-range and scanning times below two minutes.

© 2008 Optical Society of America

OCIS Codes
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.7000) Instrumentation, measurement, and metrology : Transmission
(300.6495) Spectroscopy : Spectroscopy, teraherz
(110.6795) Imaging systems : Terahertz imaging

ToC Category:
Instrumentation, Measurement, and Metrology

Original Manuscript: March 13, 2008
Revised Manuscript: April 25, 2008
Manuscript Accepted: April 25, 2008
Published: June 4, 2008

D. Banerjee, W. von Spiegel, M. D. Thomson, S. Schabel, and H. G. Roskos, "Diagnosing water content in paper by terahertz radiation," Opt. Express 16, 9060-9066 (2008)

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  1. S. J. Hashemi and W. J. M. Douglas, "Moisture nonuniformity in drying paper: measurement and relation to process parameters," Drying Technology 21, 329-347 (2003). [CrossRef]
  2. J. F. Pugh, "The infrared measurement of surface moisture in paper," Tappi,  63, 131-134 (1980).
  3. R. Kuusela, Infrared moisture measurement of paper, board and pulp, Ph.D. Thesis, University of Kuopio, Finland, (1990).
  4. R. Boulay, R. Gagnon, D. Rochette, and J. R. Izatt, "Paper sheet moisture measurements in the far infrared," Int. J. Infrared Millim. Waves 5, 1221-1234 (1984). [CrossRef]
  5. D. M. Mittleman, R. H. Jacobsen, and M. C. Nuss, "T-Ray imaging," IEEE J. Sel. Top. Quantum Electron. 2, 679-692 (1996). [CrossRef]
  6. T. Yasui and T. Araki, "Sensitive measurement of water content in dry material based on low-frequency terahertz time-domain spectroscopy," Proc. of SPIE 6024, 60240A, 69-74 (2005).
  7. C. Rønne, P.-O. ??strand, and S. R. Keiding, "THz spectroscopy of liquid H2O and D2O," Phys. Rev. Lett. 82, 2888-2891 (1999). [CrossRef]
  8. C.W. Robertson, B. Curnutte, and D. Williams, "The infrared spectrum of water," Mol. Phys. 26, 183-191 (1973). [CrossRef]
  9. J. Xu, K. W. Plaxco, and S. J. Allen, "Absorption spectra of liquid water and aqueous buffers between 0.3 and 3.72 THz," J. Chem. Phys. 124, 036101 1-3 (2006). [CrossRef] [PubMed]
  10. J. T. Kindt and C. A. Schmuttenmaer, "Far-infrared dielectric properties of polar liquids probed by femtosecond terahertz pulse spectroscopy," J. Phys. Chem. 100, 10373-10379 (1996). [CrossRef]
  11. S. Hadjiloucas, L. S. Karatzas, and W. J. Bowen, "Measurement of leaf water content using terahertz radiation," IEEE Trans. Microwave Theory Tech. 47, 142-149 (1999). [CrossRef]
  12. K. J. Siebert, H. Quast, R. Leonhardt, T. Löffler, M. Thomson, T. Bauer, H. G. Roskos, and S. Czasch, "Continuous-wave all-optoelectronic terahertz imaging," Appl. Phys. Lett. 80, 3003-3006 (2002). [CrossRef]
  13. N. Hasegawa, T. Löffler, M. Thomson, and H. G. Roskos, "Remote identification of protrusions and dents on surfaces by THz reflectometry with spatial beam filtering and out-of-focus detection," Appl. Phys. Lett. 83, 3996-3998 (2003). [CrossRef]
  14. T. Löffler, T. Bauer, K. Siebert, H. Roskos, A. Fitzgerald, and S. Czasch, "Terahertz dark-field imaging of biomedical tissue," Opt. Express 9, 616-621 (2001). [CrossRef] [PubMed]
  15. T. Löffler, T. Hahn, M. Thomson, F. Jacob, and H. G. Roskos, "Large-area electro-optic ZnTe terahertz emitters," Opt. Express 13, 5353-5362 (2005). [CrossRef] [PubMed]
  16. T. Löffler, M. Kre??, M. Thomson, T. Hahn, N. Hasegawa, and H. G. Roskos, "Comparative performance of terahertz emitters in amplifier-laser-based systems," Semicond. Sci. Technol. 20, S134-S141 (2005). [CrossRef]
  17. T. Löffler, T. May, C. am Weg, A. Alcin, B. Hils and H. G. Roskos, "Continuous-wave terahertz imaging with a hybrid system," Appl. Phys. Lett. 90, 091111 1-3 (2007). [CrossRef]
  18. A. Luukanen, L. Grönberg, P. Helistö, J. S. Penttilä, H. Seppä, H. Sipola, C. R. Dietlein, and E. N. Grossman, "An array of antenna-coupled superconducting microbolometers for passive indoors real-time THz imaging," Proc. of SPIE Vol. 6212, 62120Y 1-9 (2006). [CrossRef]
  19. A. Lisauskas, W. von Spiegel, S. Boubanga-Tombet, A. El Fatimy, D. Coquillat, F. Teppe, N. Dyakonova, W. Knap, and H. G. Roskos, "Terahertz imaging with GaAS field-effect transistors," Electron. Lett. 44, 408-409 (2008). [CrossRef]
  20. A.W. M. Lee and Q. Hu, "Real-time, continuous-wave terahertz imaging by use of a microbolometer focal-plane array," Optics Lett. 30, 2563-2565 (2005). [CrossRef]
  21. A. W. M. Lee, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Real-time imaging using a 4.3-THz quantum cascade laser and a 320 ?? 240 microbolometer focal-plane array," IEEE Photon. Technol. Lett. 18, 1415-1417 (2006). [CrossRef]

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