During the life of a high-power laser chain, optical components may be damaged due to local high fluence levels in the inhomogeneous beam. The origin of the laser damage can be impurities, surface defects or flaws and cracks resulting from polishing, or it may be produced by self-focusing in the component. The aim of this study is to better understand the correlation between a surface crack on a silica optical component and laser damage. To accomplish this, calibrated indentations were made on silica samples. Observations of the sites were made with an optical microscope, and three different morphologies were recognized. Then the zones containing the indentations were irradiated (single shot mode) with a Nd Yag laser at 355 nm for various fluences. Subsequent observations of the sites were made with an optical microscope, with the aim of correlating site morphology and laser-induced damage. Some sites were believed to have undergone laser conditioning. They were further irradiated (raster scan mode) at high fluence, and some evidence for a laser conditioning effect was obtained.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.