Automatic inspection device for locating microscopic inclusions in optical components

Automatic inspection of large optical components for the presence of microscopic metallic inclusions in the parts‐per‐quadrillion concentration range is performed by a simple device in which a Q‐switched YAG laser is focused on a continuously scanned sample. Plasma emissions from inclusions are detected by a photomultiplier tube, whose output is monitored by a computer, which then generates an inclusion map. Rapid and reliable inspection of the large optical components required for a variety of high‐energy systems is now possible.