Characterization of laser induced damage sites in optical components

Optical components for large-aperture laser systems may contain a number of defect (damage) sites formed as a result of exposure to the propagating laser beam. When exposed to high-power laser irradiation, a number of damage sites tend to grow. In this work, we explore fluorescence microscopy and optical coherence tomography for the characterization of such defect sites. Fluorescence microscopy demonstrates the presence of a layer of highly emissive, and therefore absorbing, modified material. Optical coherence tomography can image the network of cracks formed around the core of the damage site. This information may be useful for the application of a mitigation process to prevent damage growth.