Terahertz Superresolution Stratigraphic Characterization of Multilayered Structures Using Sparse Deconvolution

Dong, Junliang; Wu, Xiaolong; Locquet, Alexandre; Citrin, D. S.

doi:10.1109/tthz.2017.2673542

Cited by 75 publications

(30 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Further data analysis is required to extract the whole information about the layer structure of the sample. Therefore we used the sparse deconvolution algorithm described by Citrin and coworkers very recently 16 . Assuming that the measured signal is a convolution of the incoming THz pulse and the impulse response function of the sample, the algorithm aims to reconstruct the impulse response function of the sample using the assumption, that the impulse response function is approximately sparse.…”

Section: Resultsmentioning

confidence: 99%

“…In comparison to well-established techniques such as conventional X-ray and X-ray computed tomography (CT) 9,10 , THz time-domain imaging was first demonstrated in 1995 11 . Due to its potential in non-invasive material testing 12–15 with a depth resolution in the submillimeter range 16–19 , THz TDI has aroused much interest in recent years. The interaction mechanisms of matter with X-ray radiation are fundamentally different from those with THz waves.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of a robotic THz imaging system for sub-surface analysis of ancient human remains

Stübling

Rehn

Siebrecht

et al. 2019

Sci Rep

View full text Add to dashboard Cite

We used a robotic-based THz imaging system to investigate the sub-surface structure of an artificially mummified ancient Egyptian human left hand. The results obtained are compared to the results of a conventional CT and a micro-CT scan. Using such a robotic THz system promises new insights into the sub-surface structure of human remains. The depth resolution of the THz images exceeds the resolution of a conventional CT scan and is comparable with a micro-CT scan. The advantage of THz measurements over micro-CT scans is the fact that even comparatively large samples, like complete bodies, can be scanned. These would not fit into a conventional micro-CT scanner.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Application of a robotic THz imaging system for sub-surface analysis of ancient human remains

Stübling

Rehn

Siebrecht

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…6 was performed 3000 times with the regulation parameter λ = 0.4 and the step size . Detailed information on the accuracy of the algorithm can be found in our previous results 24 .…”

Section: Methodsmentioning

confidence: 99%

“…This feature enables us to exploit the sparse constraint and retrieve the impulse-response function by sparsity-based time-domain deconvolution. Here we present THz reflectometry with subwavelength depth resolution for stratigraphic characterization based on a sparsity-based time-domain deconvolution algorithm as developed by our group 24 , which enables us to show the detailed stratigraphy of a 17th century easel painting based on THz reflectometry for the first time to our knowledge. The paint layers on the canvas support of this painting are significantly thinner than the dominant wavelength in the available THz spectrum; thus, the THz echoes reflected from the paint layers on the supporting canvas of this painting are strongly overlapped in the first cycle of the reflected THz signal.…”

Section: Introductionmentioning

confidence: 99%

Global mapping of stratigraphy of an old-master painting using sparsity-based terahertz reflectometry

Dong

Locquet

Melis³

et al. 2017

Sci Rep

Self Cite

View full text Add to dashboard Cite

The process by which art paintings are produced typically involves the successive applications of preparatory and paint layers to a canvas or other support; however, there is an absence of nondestructive modalities to provide a global mapping of the stratigraphy, information that is crucial for evaluation of its authenticity and attribution, for insights into historical or artist-specific techniques, as well as for conservation. We demonstrate sparsity-based terahertz reflectometry can be applied to extract a detailed 3D mapping of the layer structure of the 17th century easel painting Madonna in Preghiera by the workshop of Giovanni Battista Salvi da Sassoferrato, in which the structure of the canvas support, the ground, imprimatura, underpainting, pictorial, and varnish layers are identified quantitatively. In addition, a hitherto unidentified restoration of the varnish has been found. Our approach unlocks the full promise of terahertz reflectometry to provide a global and detailed account of an easel painting’s stratigraphy by exploiting the sparse deconvolution, without which terahertz reflectometry in the past has only provided a meager tool for the characterization of paintings with paint-layer thicknesses smaller than 50 μm. The proposed modality can also be employed across a broad range of applications in nondestructive testing and biomedical imaging.

show abstract

“…By exploiting the sparse constraint, i.e., the expectation that only a limited number of temporal data points have nonzero values in the impulseresponse function, THz sparse deconvolution developed in Ref. [22], is able to provide a clear representation of the impulse-response function with sharp pulses, and increase the depth-resolution to ∼ μm 45 in air given the spectral bandwidth of our apparatus.…”

Section: Thz Subsurface Spectral Imagingmentioning

confidence: 99%

Visualization of subsurface damage in woven carbon fiber-reinforced composites using polarization-sensitive terahertz imaging

Dong

Pomarède

Chehami

et al. 2018

NDT & E International

Self Cite

View full text Add to dashboard Cite

Polarization-sensitive terahertz imaging is applied to characterize subsurface damage in woven carbon fiberreinforced composite laminates in this study. Terahertz subsurface spectral imaging based on terahertz deconvolution is tailored and applied to detect, in a nondestructive fashion, the subsurface damage within the first ply of the laminate caused by a four-point bending test. Subsurface damage types, including matrix cracking, fiber distortion/fracture, as well as intra-ply delamination, are successfully characterized. Our results show that, although the conductivity of carbon fibers rapidly attenuates terahertz propagation with depth, the imaging capability of terahertz radiation on woven carbon fiber-reinforced composites can nonetheless be significantly enhanced by taking advantage of the terahertz polarization and terahertz deconvolution. The method demonstrated in this study is capable of extracting and visualizing a number of fine details of the subsurface damage in woven carbon fiber-reinforced composites, and the results achieved are confirmed by comparative studies with X-ray tomography.

show abstract

Terahertz Superresolution Stratigraphic Characterization of Multilayered Structures Using Sparse Deconvolution

Cited by 75 publications

References 17 publications

Application of a robotic THz imaging system for sub-surface analysis of ancient human remains

Application of a robotic THz imaging system for sub-surface analysis of ancient human remains

Global mapping of stratigraphy of an old-master painting using sparsity-based terahertz reflectometry

Visualization of subsurface damage in woven carbon fiber-reinforced composites using polarization-sensitive terahertz imaging

Contact Info

Product

Resources

About