Laser based intervention on historical stained glasses

Stained glasses form an important element in human history. Since stained glasses are multifunctional, they have been utilized both in religious and civil architecture. Various conservation techniques such as mechanical, chemical, and the latest one being laser-based cleaning have been utilized. This work aims at making contributions to the knowledge about laser-glass interaction. The three main laser-glass interactions are photo-thermal, photo-chemical, and photo-mechanical. Experiments were carried out in burst and in continuous mode using a 800 ps n-IR laser with a wavelength of 1064nm. A pulsed/burst mode produces a sequence of a defined number of pulses with a high repetition rate. Contemporary glasses and historical pieces were used. The results realized will be important in the establishment of a laser tool selection criterion for decontamination/conservation of actual in-situ historic stained glasses and also develop a dynamic, automated, or semi-automated laser conservation method for historic glass. Complementary analytical techniques used include scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), confocal microscopy among others. The generally expected outcomes are to develop a practical criterion to apply lasers in cultural heritage; develop skills necessary to select, operate safely and apply lasers to problems in cultural heritage materials in general.This work was presented at the conference: ''Latest Technologies applied to the Conservation of Cultural Heritage: problems and solutions'' held between 25th and 27th November 2019 at the University of Zaragoza Spain