Diagnostics tools for subsurface damage characterization of ground silica parts

Subsurface cracks in fused silica optics are known to be damage initiators under laser irradiation. Each step of optic production, from sawing to polishing, creates its own type of cracks. An efficient optic manufacturing process requires that each production step removes cracks from the previous step. The extent of cracks has to be measured for each production step. We review and compare different subsurface damage (SSD) characterization techniques applied to ground and fine ground fused silica samples.