The laser removal of unwanted layers constituted by materials of diverse origin (organic and inorganic), assembled in mixtures (e.g., thick pollution, burial accumulations) or in layers (e.g., multiple protective, metallic, dirt and/or overpaint layers) on weathered, even fragile, original surfaces. The laser action is based on the process of ablation or vaporization and it offers unique possibilities in surface cleaning as it entails precise control, material selectivity and immediate feedback. These attributes are particularly important in Heritage conservation and within the last twenty years, lasers have evolved as exceptionally practical, and at the same time, delicate cleaning tools. This FIXLAB possess a variety of pulsed laser sources emitting in the ultraviolet, visible and infrared spectral ranges with pulse duration in the nanosecond and femtosecond regimes. Laser cleaning investigations are carried out in the installation on a large variety of heritage materials, including varnished paintings, polychromes on wood or stone, heritage stone with pollution and/or biodegradation crusts, metal substrates with corrosion layers, paper and parchment based documents and other materials. Studies aim at determining the most adequate laser parameters and the most convenient methodologies (choice of laser wavelength, dual irradiation schemes, etc.) for a safe laser cleaning treatment according with material properties and state of conservation.
archaeological object and site, architecture, art, decorative arts, film, mosaics, painting, sculpture, textile
fossil, mineral, shell, skeleton
ceramic (clay/mud brick/terracotta/earthenware/stoneware/porcelain), glass, stone, metal and metallurgical By-Products, pigment
binding media, glues, wood, paper, textiles, varnishes
Different laser sources are available for laser cleaning investigations, including Q-switched Nd:YAG lasers (with variable repetition rate) and excimer lasers with pulse duration in the nanosecond domain and a continuous CO_2 laser. Different optical and opto-mechanical components for control and guidance of the laser beams to the sample are also available. Lateral and axial spatial...
IESL-FORTH holds a number of laser systems with different wavelength, pulse duration and energy output characteristics available for laser cleaning investigations such as: A) Q-switched Nd:YAG lasers emitting both nano- and pico-second laser pulses at various wavelengths (such as 1064, 532, 355, 266 and 213nm) B) various excimer lasers emitting nano, pico and femto-second pulses...