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A methodology for dynamic material characterizations via terahertz time-domain spectroscopy. Lesack, Nikolai; Fredeen, Naomi V.; Jirasek, Andrew; Holzman, Jonathan

Abstract

In this work, the challenges of terahertz (THz) time-domain spectroscopy on complex (multilayer) samples with time-varying (dynamic) characteristics are addressed. The challenges appear in characterizations of the refractive index and extinction coefficient, as etalon artifacts due to internal reflections, and are accentuated in multilayer structures having dynamic and low-loss materials, such as biomolecular materials. This is because nonidealities may form as airgaps at the interfaces and as inhomogeneity in the bulk. The proposed methodology addresses the challenges by introducing a generalized model that accommodates dynamic formation of airgaps and inhomogeneity. It is shown that the generality of the model allows it to mitigate etalon artifacts and yield a highly accurate representation of the material characteristics, with low systematic error, even for low-loss materials. The methodology is applied to characterizations of quartz and glucose in the THz spectrum to see fine detail in the characteristics of quartz and the crystallization of glucose.

Item Metadata

Title
A methodology for dynamic material characterizations via terahertz time-domain spectroscopy.
Creator
Lesack, Nikolai; Fredeen, Naomi V.; Jirasek, Andrew; Holzman, Jonathan
Publisher
IEEE
Date Issued
2019-08
Description
In this work, the challenges of terahertz (THz) time-domain spectroscopy on complex (multilayer) samples with time-varying (dynamic) characteristics are addressed. The challenges appear in characterizations of the refractive index and extinction coefficient, as etalon artifacts due to internal reflections, and are accentuated in multilayer structures having dynamic and low-loss materials, such as biomolecular materials. This is because nonidealities may form as airgaps at the interfaces and as inhomogeneity in the bulk. The proposed methodology addresses the challenges by introducing a generalized model that accommodates dynamic formation of airgaps and inhomogeneity. It is shown that the generality of the model allows it to mitigate etalon artifacts and yield a highly accurate representation of the material characteristics, with low systematic error, even for low-loss materials. The methodology is applied to characterizations of quartz and glucose in the THz spectrum to see fine detail in the characteristics of quartz and the crystallization of glucose.
Subject
adsorption; electromagnetic wave propagation; refraction; signal processing; spectroscopy; terahertz-time-domain spectroscopy; dynamic material characterization
Genre
Article
Type
Text
Language
eng
Date Available
2021-03-31
Provider
Vancouver : University of British Columbia Library
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International
DOI
10.14288/1.0396429
URI
http://hdl.handle.net/2429/77676
Affiliation
Applied Science, Faculty of; Arts and Social Sciences, Irving K. Barber Faculty of (Okanagan); Engineering, School of (Okanagan)
Citation
N. I. Lesack, N. V. Fredeen, A. Jirasek, and J. F. Holzman, "A methodology for dynamic material characterizations via terahertz time-domain spectroscopy," IEEE Transactions on Terahertz Science and Technology, vol. 10, pp. 282-291, 2020.
Publisher DOI
10.1109/TTHZ.2020.2972945
Peer Review Status
Reviewed
Scholarly Level
Faculty
Copyright Holder
IEEE
Rights URI
http://creativecommons.org/licenses/by-nc-nd/4.0/
Aggregated Source Repository
DSpace

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Attribution-NonCommercial-NoDerivatives 4.0 International