4. Laser blasting

This process is based on a photomechanical reaction induced by the interaction between a light beam with very short pulses (10 to 30 ns) and high instantaneous power, and a surface layer of pollution (grease, oxides, paint, etc.) [71][72][73] . The high energy absorbed by the surface layer creates a plasma which, when expanded, generates a shock wave. This breaks up the layer of pollutants into fine particles without damaging the surface. The low thermal output, in the order of a few tens of watts, avoids any damaging heating of the workpiece (figure 7 ).