Confocal Terahertz Imaging of Ancient Manuscripts

Flammini, M.; Bonsi, C; Ciano, Chiara; Giliberti, Valeria; Pontecorvo, E.; Italia, Paola Maria Carmela; DelRe, Eugenio; Ortolani, Michele

doi:10.1007/s10762-016-0338-x

Cited by 14 publications

(10 citation statements)

References 18 publications

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“…It uses pinholes that act as spatial filter, reducing the THz beam size to sub-wavelength dimensions and blocking outside the cone of light. This results in increased lateral and depth resolutions [122,123]. However, the aperture introduces an immense loss of THz light intensity at deep sub-wavelength resolutions (<λ/10) [124], caused by the low frequency cut-off [125] and optical coupling loss.…”

Section: Tpi Near-field Systemsmentioning

confidence: 99%

THz Pulsed Imaging in Biomedical Applications

et al. 2020

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Recent advances in technology have allowed the production and the coherent detection of sub-ps pulses of terahertz (THz) radiation. Therefore, the potentialities of this technique have been readily recognized for THz spectroscopy and imaging in biomedicine. In particular, THz pulsed imaging (TPI) has rapidly increased its applications in the last decade. In this paper, we present a short review of TPI, discussing its basic principles and performances, and its state-of-the-art applications on biomedical systems.

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Section: Tpi Near-field Systemsmentioning

confidence: 99%

THz Pulsed Imaging in Biomedical Applications

et al. 2020

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“…Terahertz radiation is capable of deep penetration through numerous and different media; thus, it has been used to identify ancient manuscripts or hidden text in a variety of studies [52,53]. THz radiation lies in the far-infrared region of the electromagnetic spectrum ranging from 0.1 to 10 THz (3.3-333 cm −1 ).…”

Section: Terahertz Time-domain Imaging (Thz-tdi)mentioning

confidence: 99%

Non-Linear Microscopy: A Well-Established Technique for Biological Applications towards Serving as a Diagnostic Tool for in situ Cultural Heritage Studies

Mari

Filippidis

2020

Sustainability

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A range of sophisticated imaging techniques have been developed in recent years that can reveal the surface structure of cultural heritage objects with varying precision. In combination with various spectroscopic methods, they allow the study of the chemical composition of the object; thus, conclusions can be drawn about the origin of the object or its initial components, method, or time of creation, authenticity, mechanisms of degradation, and ways of further conservation. At present, different techniques can be applied to a wide range of cultural heritage objects, such as varnishes, paintings, archaeological objects, binding media, paper-based documents, parchments, marbles, frescoes, as well as various objects made of leather, fabric, stone, ceramics and glass, wood, or metal. One of the main needs in the study of cultural heritage (CH) is the transportability/portability of the research equipment, since many pieces under investigation cannot be moved to the laboratory, either because of their size, inseparability (for example, frescoes on walls, mural paintings in caves), or the threat of damage. In this work, we briefly overview the main optical- and laser-based methods used for the study of cultural heritage objects indicating the scope of their application, and we focus on the applications of non-linear microscopic methods for the investigation of a series of artifacts. We also discuss all the requirements for the construction of a prototype transportable non-linear optical system that will be used as a novel diagnostic tool for in situ studies of CH assets. The availability of such a transportable workstation will significantly improve the study and characterization of various types of CH objects and will constitute an extremely useful diagnostic tool for heritage scientists dealing with a variety of investigations.

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“…However, this approach can be prohibitive when measuring several hidden layers due to the limited penetration capabilities of optical wavelengths. On the contrary, terahertz radiation presents a high penetration depth within several media of interest and thus has been employed for the identification of hidden text and ancient manuscripts by several studies . Recently, Redo‐Sanchez et al used time‐domain spectroscopic imaging to generate layer‐by‐layer images of texts, managing to extract content from a nine‐page stack …”

Section: Introductionmentioning

confidence: 99%

Uncovering the hidden content of layered documents by means of photoacoustic imaging

Tserevelakis

Tsagkaraki

Siozos

et al. 2018

Strain

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We introduce a novel diagnostic approach for the uncovering of hidden content in layered documents, based on a photoacoustic imaging set‐up with optimised acoustic detection parameters. By exploiting the laser‐induced ultrasound following the intense absorption of pulsed optical radiation by printed ink, this traditional biomedical imaging method is proven capable of revealing text characters buried under several layers of stacked paper sheets at high spatial resolution and excellent contrast levels. Such a remarkable performance benefits from the effective combination of strong light scattering by paper fibrils and the virtually unobstructed propagation of the generated ultrasonic waves through multiple layers, enabling thus the accurate recording of text, even in double‐sided prints, with minimum shadowing artefacts. The imaging effectiveness, the implementation simplicity, the robustness, and the relatively low‐cost features offered by the proposed photoacoustic modality are anticipated to contribute in its wide adoption by the preservation of cultural heritage community, as a powerful diagnostic tool for the in‐depth investigation of complex multilayered objects.

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Confocal Terahertz Imaging of Ancient Manuscripts

Cited by 14 publications

References 18 publications

THz Pulsed Imaging in Biomedical Applications

THz Pulsed Imaging in Biomedical Applications

Non-Linear Microscopy: A Well-Established Technique for Biological Applications towards Serving as a Diagnostic Tool for in situ Cultural Heritage Studies

Uncovering the hidden content of layered documents by means of photoacoustic imaging

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