The Physical Principles Of Laser Cleaning 1. The laser beam is absorbed by the surface contaminants. This absorption process converts the laser energy into heat, causing the contaminants to rapidly heat up. 2. The absorbed energy results in the formation of a rapidly expanding plasma, a highly ionized unstable gas. This plasma generates a shockwave as it expands. 3. The shockwave produced by the plasma causes the contaminants to fragment and be removed from the surface. The force of the shockwav