THz spectrometer with fiber coupled antennas: Preliminary application test for characterizing stone artefact

In this work the potential of a THz spectrometer with fiber coupled antennas for characterizing stone artefacts of cultural interest has been investigated for the first time. Systematic measurements have been carried out on various limestone and marble quarry samples, which allowed estimating the depth ranges of interest and the depth range to be investigated and their refractive indexes and the depth ranges We have characterized the pulse shape, and this allowed us to choose the thickness range of the samples to be investigated. We have measured the refractive index of several. We have attributed to porosity the different refractive index observed. This data have been used to characterize the degradation of a marble column from Florence´s Cathedral. In particular it has been observed sulfation and crust rising.