1. Confocal Terahertz Imaging of Ancient Manuscripts.
- Author
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Flammini, Mariano, Bonsi, Claudia, Ciano, Chiara, Giliberti, Valeria, Pontecorvo, Emanuele, Italia, Paola, DelRe, Eugenio, and Ortolani, Michele
- Subjects
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TERAHERTZ time-domain spectroscopy , *PRESERVATION of manuscripts , *CONFOCAL microscopy , *PRESERVATION of parchment , *NEAR infrared spectroscopy - Abstract
Terahertz imaging has the potential to identify and decipher portions of ancient manuscripts, which may be unreadable at infrared and visible wavelengths. We use a scanning confocal terahertz microscope to scan a medieval parchment with music notes and pentagrams written with different inks. The microscope is based on a continuous-wave solid-state source at 0.3 THz, emitting in the free space with a horn antenna, and a high numerical-aperture ellipsoidal reflector. We present terahertz images with diffraction-limited lateral resolution of approximately 0.5 mm, where the different inks all give similar high contrast. Symbols written on the 'verso' side of the parchment, barely glimpsed in the near-infrared photograph, leave a clear imprint in the terahertz images. Artifacts due to imperfect flatness of the parchment are also briefly discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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