Excimer laser for fundamental studies in cleaning hewn stone and medieval glass
2003; Elsevier BV; Volume: 4; Linguagem: Inglês
10.1016/s1296-2074(02)01188-3
ISSN1778-3674
AutoresJens Hildenhagen, K. Dickmann,
Tópico(s)Building materials and conservation
ResumoThe UV wavelength at 248 nm of an excimer laser was used for basic investigations in cleaning of various encrusted sandstones as well as corroded medieval glass. Due to the combination of UV wavelength and short pulse duration (20–40 ns), this laser enables a removal with very low thermal load onto the artwork. Our studies have shown that this is true for the removal of dense crusts, bio-layers and organic layers (due to former conservation) from medieval glass. The potential of excimer lasers in this field will be demonstrated by various partially laser cleaned original glass fragments from the Cathedrals of Cologne and Meissen (Germany). In comparison to other wavelengths (IR, VIS) also being used within this study, only the excimer laser seems to be applicable in glass cleaning. This laser type is also suitable to remove crusts from sandstone artwork with negligible thermal effects on the original surface. The benefit of excimer lasers in this field is the sensitive removal layer by layer with each laser pulse. The typical thickness being removed is <1 μm per pulse. On the other hand, the cleaning rate of extended areas is much lower as compared to state-of-the-art Nd:YAG cleaning equipment.
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