Rapid vaporization mechanism in enclosed laser ablation

Enclosed laser ablation is a new technique, where a laser absorbent surface is contained under a transparent film and laser treated. So far, work has been carried out upon thin films of aluminium sandwiched between two polymer sheets and has shown to successfully re-distribute the aluminium from a flat, opaque film to a series of mutually exclusive particles randomly distributed throughout the film. In this paper, experimental observations and heating calculations were used as evidence for a proposed mechanism by which enclosed laser metal dispersion occurs when the material was treated using ideal laser parameters. The mechanism proposed involves a rapid vaporization of the aluminium layer and a resolidification and particle forming process within the polymer substrate. In addition to this, analysis was carried out upon the dispersed particles and the relationship between their size and the process parameters were examined.