Application of laser in conservation and restoration of historical building

Cultural Heritage has many analytical and treatment needs both in the field of conservation than in restoration. The laser therefore found a ready-made place in this area. We find first the different application of laser cleaning. The LRMH was the initiative of creating the first field prototype used in the field for cleaning stone in particular. A tour of the Cathedral of France to test this method had been achieved in the early 90s. Then, many have phenomenological and physical studies were conducted to understand the mechanisms involved during the cleaning action. In analytical technology, LIBS (Laser Induced Breakdown Spectroscopy) is used for in situ identification of pigments, salts, metals or other materials. This laser technique present a lot of advantages: portability, analysis of light elements, stratigraphic analysis capability ...The LRMH was the first laboratory depending from a ministry of culture to get the technology and to apply it systematically in situ (Saint-Savin sur Gartemps abbey...). In addition, more recently, a methodology for converting pigments by continuous laser was developed in the laboratory, thus extending the scope of the use of laser. We review these techniques and their application based on studies that occur in our laboratory.