New photographic technique for observing bulk laser damage

A damage site camera was developed to record the onset of bulk laser damage in materials. The camera images and magnifies the damage track using forward scattered laser light. Employing this camera, the presence of very small (10 m) damage sites with densities as low as 10/cc were detected. The camera is used at oblique incidence to the part being tested. Discrete damage sites generated within the bulk of some materials, such as silicate glass, fluorophosphate glass, and KDP crystals, by 1-ns 1064-nm laser were observed.