Process for repairing large scratches on fused silica optics

Scratches at the surface of fused silica optics can be detrimental for the performance of optical systems because they initiate damage on the optic but also they perturb the amplitude or phase of the transmitted laser light. Removing scratches by conventional polishing techniques can be time consuming as it is an iterative and long process, especially when hours of polishing time are required to obtain very high surface accuracy. So we have investigated ways to remove them with local laser processing. The silica is then heated at temperature higher than the softening point to heal the cracks.