A theoretical model for laser removal of particles from solid surfaces

A theoretical model for laser cleaning of microparticles from solid surfaces was established by taking the adhesion force (van der Waals force) and cleaning force (due to thermal expansion) into account. The cleaning conditions and threshold can be obtained from this model. Theoretical predictions have been verified by the experimental results for removing aluminium particles from a quartz substrate. It was found that laser irradiation from the back of the substrate is more effective in removing particles with different sizes than that from the front. With laser irradiation from the back, large particles can be removed more easily than small ones. However, with laser irradiation from the front, smaller particles can be removed more easily.