Surface defect generation in optical materialsunder high fluencelaser irradiation in vacuum

Abstract

It is shown that irradiation of optical materials with high fluence ultraviolet laser pulses at low pressure leads to a rapid growth in the surface defect population and degradation of their performance. Experiments have been performed in nonlinear KH2PO4 crystal and in fused silica, and surface defect populations have been observed following a few tens of high fluence 351nm pulses.