Terahertz Imaging and Spectroscopy

Coordinators: David S. Citrin and Alexandre Locquet

Research Themes

Transmission and Reflection Imaging of fiber-reinforced composites

Reflection Imaging of Metal Coatings

THz applications in cultural heritage conservation science

Recent Publications

J. Dong, A. Locquet, D. S. Citrin,"Terahertz Quantitative Nondestructive Evaluation of Failure Modes in Polymer-Coated Steel",  to appear in IEEE Journal of Selected Topics in Quantum Electronics (2016).

J. Dong, J. Bianca Jackson, M. Melis, D. Giovannacci, G. C. Walker, A. Locquet, J.W. Bowen, and D. S. Citrin, "Terahertz Frequency-Wavelet Domain Deconvolution for Stratigraphic and Subsurface Investigation of Art Painting", submitted (2016). 

J. Dong, B. Kim, A. Locquet, P. McKeon, N. Declercq, D.S. Citrin, "Nondestructive evaluation of forced delamination in glass fiber-reinforced composites by terahertz and ultrasonic waves", Composites Part. B 79, 667 (2015). Impact Factor: 3.85.

J. Dong, A. Locquet, and D. S. Citirn, "Enhanced Terahertz Imaging of Small Forced Delamination in Woven Glass Fiber-reinforced Composites with Wavelet De-noising", Journal of Infrared, Millimeter, and Terahertz Waves 37, 289 (2016). Impact Factor: 1. 942 .

J. Dong, A. Locquet. N. Declercq, and D. S. Citrin, "Polarization-resolved terahertz imaging of intra- and inter-laminar damages in hybrid fiber-reinforced composite laminate subject to low-velocity impact", Composites Part. B 92, 167 (2016). Impact Factor: 3.85.

Conference Participations

J. Dong, A. Locquet, D. S. Citrin, "Terahertz Reflective Imaging of Damage Mechanisms in the Coating on Metal Substrate",  to be presented in IRMMW-THZ 2016, Copenhagen, Denmark (2016).

J. Binaca Jackson, M. Melis, J. Dong, D. Giovannacci, G. Walker, A. Locquet, J. Bowen, D. S. Citrin, "Comparative Study of Mid-20th C. Art Using THz and X-ray Imaging", to be presented in IRMMW-THZ 2016, Copenhagen, Denmark (2016).

J. Dong, A. Locquet, N. F. Declercq, D. S. Citrin, "Polarization-resolved Terahertz Imaging of Impact Damage in a Hybrid Fiber-reinforced Composite Laminate",  QNDE 2016, Atlanta, GA, USA (2016).

J. Dong, A. Locquet, D. S. Citrin, "3D Quantitative Damage Characterization in the Coating of a Metal Substrate with Terahertz Waves",  QNDE 2016, Atlanta, GA, USA (2016).

J. Dong, A. Locquet, D. S. Citrin, "Polarization-resolved Terahertz Imaging of Hybrid Fiber-reinforced Composite Laminate Subject to Low-velocity Impact", to be presented in CLEO:2016, San Jose, California, USA (2016).

M. Melis, J. Dong, J. Bianca Jackson, D. Giovannacci, D. S. Citrin, A. Locquet, J. Bowen, V. Detalle, and G. Rizza, “Non-invasive and innovative analysis of an Ausonio Tanda Painting Using Multiple Band-Multiple Technology Approach in the Bands of THz, NIR, Visible, UV, and X-Ray”, 5th EOS Topical Meeting on THz Science, Pecs, Hungary (2016).

J. Dong, A. Locquet, N. Declercq, and D.S. Citrin, “Terahertz Imaging of Damage Evolution in Hybrid Fiber-Reinforced Composite Laminate Subject to Low-Velocity Impact”, 7th International Workshop on Terahertz Technology and Applications, Fraunhofer IPM, Kaiserslautern, Germany (2016).

J. Dong, J. Liu, B. Kim, A. Locquet, N.F. Declercq, and D.S.Citrin, “Forced Delamination Characterization of Glass Fiber Composites using Terahertz and Ultrasonic Imaging”, International Congress on Ultrasonics (ICU) 2015, Metz, France.

J. Dong, D.S. Citrin, N. Declerq, A. Locquet, “Impact Damage Characterization in Hybrid Fiber Composites Using Terahertz Imaging in the Time and Frequency Domains,  International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THZ) 2015, Hong Kong, China.

J. Dong, A. Locquet, N.F. Declercq, and D.S.Citrin, “Delamination characterization of fiber-reinforced composites using terahertz imaging”, German THz conference 2015, Dresden, Germany.

Our publications in the field of nonlinear dynamics in photonics can be found here.


Ph.D. Students

Junliang Dong

M.S. Students

Anthony Agnesina (Supélec-Georgia Tech dual-degree student)

Context and Objectives

The terahertz region of the electromagnetic spectrum lies roughly from 100 GHz to 10 THz. It is a region where many proven techniques—approached from the low-frequency side (microwaves) or the high-frequency side (optics)—perform poorly.Until the very recent growth of availability of terahertz sources, detectors, and components, progress was slow, but is now undergoing tremendous growth.this region of the spectrum is quite rich in physical phenomena, including rotations and vibrations in both small and large molecules, molecular reconfigurations, and carrier transport phenomena in semiconductors. Many solids have vibrational modes (phonons) in this part of the spectrum. In addition, from a physical optics viewpoint, since the wavelengths in the 100 GHz-10 THz range are ~3000-30 µm, terahertz techniques provide potential to image several-micron-scale objects (wires, small mechanical systems, biological structures) that cannot be resolved with microwaves. In addition, a number of packaging and building materials and many common textiles are relatively transparent to terahertz radiation, suggesting possibilities in security imaging and detection of personnel and packages as well as the monitoring of industrial processes and nondestructive evaluation.

Terhartz imaging is ideal for the detection of defects in plastic, glass, and ceramic. Terhartz radiation is non-ionizing; measurements are contactless and do not require a coupling fluid. Terhartz reflection imaging usually allows for in-depth analysis of materials.

Former Students 

Chris Sheng (Undergrad, Fall 2014)
Amélie Martinez (Grad dual-degree student with Supélec, Spring 2014)

Contact Us

Alexandre Locquet, alocquet at georgiatech-metz dot edu

See Also our Other Research activity:


Useful Links

Experience Georgia Tech - in France


We gratefully acknowledge the financial support of the Centre National de la Recherche Scientifique, the Conseil Régional de Lorraine, the Fonds Européen de Développement Régional (FEDER), and the Institut Carnot ARTS, of which our lab is a member.