Enhanced laser cleaning via direct line beam irradiation

A fluence advantage was achieved in dry/damp laser cleaning by reduction of the laser beam dimensions. 0.1 m Al₂O₃ particles were removed from glass slides using a KrF excimer laser (248 nm). As the width of the rectangular beam was reduced, a decrease in the threshold fluence required for particle removal was observed. Modelling based on the simplified thermal–mechanical response of the substrate and particle to the laser pulse does not describe the experimental results presented here. The case of dynamic expansion must be further considered, but it is believed that other mechanisms are involved in a full explanation. PACS 42.62.Cf