Efficient laser cleaning of small particulates using pulsed laser irradiation synchronized with liquid-film deposition

Pulsed laser heating of a surface is shown to be a promising new approach for effective cleaning of small particulate contaminations. Various versions of such a technique of laser cleaning is possible, depending on where the laser irradiation is absorbed and whether a thin film is deposited on the surface to enhance the cleaning. We have observed that laser cleaning with the highest efficiency can be achieved by choosing a laser wavelength (typically ultraviolet) that is strongly absorbed by the surface, and by pulse-depositing a water film of thickness on the order of microns on the surface momentarily before the pulse laser irradiation. This permits the effective removal of particles smaller than approximately equals 20 micrometers , down to as small as 0.1 micrometers , from a solid surface, using a modest ultraviolet laser fluence of approximately equals 0.1 J/cm2.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.