Absorption phenomena in metal drilling with Nd-lasers

Abstract

An experimental investigation of the breakdown of metal reflectivity under intense radiation from an Nd-laser is presented. It includes time resolved measurements of the hemispherical reflectivity and of the pertinent target damage. The experiments show the occurrence of an absorbing layer that couples up to 80 percent of the light power into the condensed metal. The layer is formed when the surface temperature corresponds to several atmospheres of vapor pressure.