Valavanis, A, Chowdhury, S, Burnett, AD et al. (6 more authors) (2016) Diffuse-reflectance spectroscopy using a frequency-switchable terahertz quantum cascade laser. IEEE Transactions on Terahertz Science & Technology, 6 (2). pp. 341-347. ISSN 2156-342X
Abstract
We demonstrate diffuse-reflectance (DR) spectroscopy of powders using a discretely-tunable terahertz-frequency quantum cascade laser (THz QCL) with a heterogeneous active region. DR signatures were obtained at frequencies of 3.06, 3.21, 3.28 and 3.35 THz, and the relative absorption coefficients were inferred at each frequency using a Kubelka–Munk (KM) scattering model. The spectral lineshapes reproduce the absolute Beer–Lambert (BL) absorption spectra of a range of materials, which were also measured using conventional transmission-mode THz time-domain spectroscopy. It is shown that the DR technique works reliably for materials that include pharmaceutical compounds and foodstuffs, with BL absorption coefficients in the range 2–10 mm−1. This method is potentially suitable for automated material identification, without any requirement for a priori knowledge of the refractive index or scattering properties of the sampled material.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2016, IEEE. This work is licensed under a Creative Commons Attribution 3.0 License. For more information, see http://creativecommons.org/licenses/by/3.0/ |
Keywords: | Infrared spectra; Quantum cascade lasers; sub-millimeter wave technology; spectroscopy |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) > Pollard Institute (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) |
Funding Information: | Funder Grant number EU - European Union 228035 Home Office Not Known EU - European Union 247375 EPSRC EP/J002356/1 Royal Society WM110032 EPSRC EP/J017671/1 Royal Society WM150029 |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Jan 2016 15:15 |
Last Modified: | 31 Mar 2016 11:30 |
Published Version: | http://dx.doi.org/10.1109/TTHZ.2016.2515082 |
Status: | Published |
Publisher: | Institute of Electrical and Electronics Engineers (IEEE) |
Identification Number: | 10.1109/TTHZ.2016.2515082 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:93228 |