Laser cleaning works because the laser energy is absorbed by the contamination or coating. This contamination heats up, detaches, burns locally, or is removed in small particles. The trick is to ensure that the underlying base material is affected as little as possible in an undesirable way. This is only possible when the energy input, movement, and distance remain under control.
Operators do not need to be physicists, but they do need to know a few basic concepts. Power refers to how much energy is available. Time refers to how long the energy acts on or within a specific area. Material reaction refers to what that combination does to a specific surface. The practice of laser cleaning is, in fact, mastering that triangle: energy, time, and material.
A common misconception is that more power is automatically better. That is incorrect. A more powerful machine offers greater production potential, but it also reduces the margin of error. Especially with delicate surfaces, edges, thin material, and reflective substrates, more power requires more discipline. Therefore, an operator must learn not to think in terms of 'as strong as possible,' but in terms of 'sufficient, controlled, and appropriate for the purpose.' The operator's movement is also part of the process. The jet only does its job when the operator maintains a constant, logical, and safe path. Erratic movements, lingering at a single point, or constantly changing distances immediately cause differences in effect, heat input, and the appearance of the result.