1064-nm, nanosecond laser mirror thin film damage competition

This competition aimed to survey state-of-the-art near-IR high reflectors. The requirements of the coatings are a minimum reflection of 99.5% at 0 degrees incidence angle light at 1064-nm. The choice of coating materials, design, and deposition method were left to the participants. Laser damage testing was performed at a single testing facility using the raster scan method with a 3-ns pulse length laser system operating at 5 Hz in a multi-longitudinal mode. A double blind test assured sample and submitter anonymity. In addition to the laser damage resistance results, details of the deposition processes, cleaning method, coating materials and layer count are also shared. We found that hafnia/silica multilayer coatings deposited by e-beam are the most damage resistant under the test conditions.