Papyrus imaging with terahertz time domain spectroscopy (original) (raw)

Terahertz time domain spectroscopic imaging (THz-TDSI) is a non-ionizing, non-contact and nondestructive measurement technique that has been recently utilized to study cultural heritage artifacts. We will present this technique and the results of non-contact measurements of papyrus texts, including images of hidden papyri. Inks for modern papyrus specimens were prepared using the historical binder, Arabic gum, and two common pigments used to write ancient texts, carbon black and red ochre. The samples were scanned in reflection at normal incidence with a pulse with a spectral range between 0.1 and 1.5 THz. The temporal analysis of the signals provides the depth of the layer, and their frequency spectra give information about the inks.