Combined photoacoustic imaging to delineate the internal structure of paintings

• DOI: 10.1364/ol.44.000919
• Publication Date: 2019-02-07T22:08:29Z
• Authors: Alice Dal Fovo; George J. Tsereve...; Athanasia Papanik...; Giannis Zacharakis; Raffaella Fontana
• Keywords: Photoacoustic Spectroscopy; SIGNAL (programming language)

In this Letter, we present a combined photoacoustic imaging method, based on consecutive excitation using either the fundamental or second-harmonic wavelength of pulsed Nd:YAG laser for stratigraphy painted artworks. Near-infrared was employed hidden underdrawings in mock-up samples, whereas visible light used thickness mapping overlying paint through detection signal attenuation. The proposed methodology proven effective measuring thick and strongly absorbing layers, which would not be possible by means other pure optical techniques, while also enabling visualization features underneath surface. Such an implementation expands significantly applicability previously presented technique, limited to point-measurements, paves way novel application historical technical studies, as well documenting restoring operations.