LASER TECHNOLOGY FOR THE STRUCTURAL DIAGNOSTICS AND COMPOSITIONAL ANALYSIS OF CULTURAL HERITAGE OBJECTS
In the last decades significant advances have been realized as regards the development of modern technologies for the study and preservation of Cultural Heritage objects and Monuments. The Institute of Electronic Structure and Lasers (IESL) of FORTH is one of the premier locations worldwide regarding the application of laser technology in the diagnostics and conservation of works of arts and antiquities. These activities revolve around the development and application of laser cleaning methodologies, laser spectroscopic techniques for the compositional characterization of artifacts and holographic metrology techniques and imaging systems for structural diagnostics. More specifically the following laser analytical techniques have been developed and are applied in the service of Cultural Heritage objects:
Spectral Imaging enables the stratigraphic study of artworks by observation in spectral regions which human eye is not sensitive to; namely in the ultraviolet (350nm-400nm) and the near infrared (700nm-1200nm). By means of a prototype spectral imaging system, the detailed mapping of the individual layers that compose the artwork is possible, enabling thus the detection of protective coating layers, possible over-paintings, retouches and restoration interventions, the presence of surface pollutants, as well as invisible under-drawings. Comparative study of the obtained information to historic references may facilitate art historians and scholars to draw conclusions about the period that the artwork was created and the artists’ technique and potentially verify the authenticity of an artwork. Finally, through spectral imaging, significant information on the preservation state and previous interventions of the artwork can be drawn which will assist conservators to decide on the necessary conservation strategies.
Digital Holographic Speckle Pattern Interferometry (DHSPI) is a non-destructive technique able to remotely diagnose the structural condition of an artwork by detecting different types of alterations (e.g. detachments, cracks, micro-cracks). Alterations may be located either on the surface or in the interior of the artwork and may not be detectable visually. Furthermore, the recording of a holographic fingerprint of an artwork is a unique attribute characterizing solely the artwork and thus may certify its authenticity by safeguarding the object from future falsifications, replacements etc.
Laser Spectroscopic Analysis (LIBS, LIF, Raman) provides insight on the identity and composition of materials in Cultural Heritage objects.
More detailed information can be found at LASERS FOR ART SAKE site.