ABSTRACT
Currently, however, the application of femtosecond lasers to the cleaning of artifacts has been limited to small surface areas, and to a limited volume of the order of few mm3 at most. This is due to the fact that the low energy of the ultrashort laser pulse requires tight focusing to achieve the required ablation threshold intensity, which is of the order 1011 W/cm21012 W/cm2. Moreover, the lower ablated mass per pulse, as compared with conventional long-pulse lasercleaning techniques, requires a significant increase in the laser repetition rate to achieve a reasonable rate of surface treatment. A technique is therefore required to provide fast and precise scanning of the laser beam over the surface area to be treated.
