Terahertz time-domain spectroscopy of absorbing materials


  • Frédéric Garet Université de Savoie
  • B. Blampey Université de Savoie
  • J.-L. Coutaz Université de Savoie




In this paper, we study the noise-limited precision on the complex refractive index value of materials in the terahertz frequency range as determined by terahertz time-domain spectroscopy. As absorbing samples are almost opaque, transmission measurements are not suitable to determine the refractive index and reflection indices have to be employed instead, but at the expense of precision. We give rules to select the most adapted technique, i.e. in transmission or in reflection, for any given sample of arbitrary transparence

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  1. M. van Exter and D. Grischkowsky, "Optical and electronic properties of doped silicon from 0.1 to 2 THz", Appl. Phys. Lett. 56, 1694 (1990); CrossRef
  2. Sensing with Terahertz Radiation, ed. D. Mittleman, Springer Series in Optical Sciences Vol. 85, Berlin (2003).DirectLink
  3. For example: http://www.menlosystems.com; , http://www.rainbowphotonics.com; , http://www.teraview.com; , http://www.ekspla.com; , http://www.picometrix.com; , http://www.zomega-terahertz.com; .
  4. T. Dorney, R. Baraniuk, and D. Mittleman, "Material parameter estimation with terahertz time-domain spectroscopy", J. Opt. Soc. Am. A 18, 1562 (2001); CrossRef
  5. I. Pupeza, R. Wilk, and M. Koch, "Highly accurate optical material parameter determination with THz time-domain spectroscopy", Opt. Exp. 15, Issue 7, 4335 (2007). CrossRef
  6. L. Thrane, R. H. Jacobsen, P. U. Jepsen, and S. R. Keiding, "THz reflection spectroscopy of liquid water", Chem. Phys. Lett. 240, 330 (1995); CrossRef
  7. S. C. Howells and L. A. Schlie, "Transient terahertz reflection spectroscopy of undoped InSb from 0.1 to 1.1 THz", Appl. Phys. Lett. 69, 550 (1996). CrossRef
  8. P. Uhd Jepsen and B. M. Fischer, "Dynamic range in terahertz time-domain transmission and reflection spectroscopy", Optics Letters 30, 29 (2005). CrossRef
  9. L. Duvillaret, F. Garet, J.-L. Coutaz, "Influence of noise on the characterization of materials by terahertz time-domain spectroscopy", J. Opt. Soc. Amer. B17, 452 (2000). CrossRef

Author Biography

Frédéric Garet, Université de Savoie

Faculty of Physics,

Optics Division




How to Cite

F. Garet, B. Blampey, and J.-L. Coutaz, “Terahertz time-domain spectroscopy of absorbing materials”, Photonics Lett. Pol., vol. 4, no. 3, pp. pp. 88–90, Sep. 2012.