Investigation of The Er:Yag Laser at 2.94mm to Remove Lichens Growing on Stone

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Publication Type:

Journal Article


Decruz, Adele; Culberson, Chicita; Wolbarsht, Myron L.; Andreotti, Alessia; Colombini, Maria Perla; Pinna, Daniela;


Studies in Conservation, Volume 54, Number 4, p.268-277 (2009)


The analysis of the surface ablation of the removal of lichens from stone by use of a free-running pulsed Er:YAG laser (erbium-doped yttrium, aluminium, garnet crystal) at a wavelength of 2.94 ?m demonstrated the complete destruction of the lichen cell wall. In this paper these results are confirmed, and experiments are described which seek to determine the physical/ chemical mechanism of the ablation process using pyrolysis gas chromatography–mass spectrometry (pyrolysis GC-MS), highperformance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and fluorescence microscopy.