APS -Annual Meeting of the APS Four Corners Section- Event - Laser induced damage characteristics of optical thin film with ion assisted planarization and annealing

摘要

Ion beam sputtering growth of amorphous oxides coupled with processing using Ar ion assist is termed extit{planarization}. This process was introduced by our team reducing defect cross-section on pre-patterned substrates by up to 90{%} and increasing laser damage performance by 10x The effects of SiO$_{mathrm{2}}$ planarization processing on the laser damage resistance of single, bilayers, and multilayer coatings of HfO$_{mathrm{2}}$ and SiO$_{mathrm{2}}$ is investigated at pulse durations of 9ps and 220ps. Planarized samples experience a large increase in absorption loss at 1extmu m wavelength, which is reduced after in-air annealing suggesting presence of oxygen point defects. It is shown the laser damage threshold reduces with planarized SiO$_{mathrm{2}}$ layers directly implemented compared to control samples at both pulse durations. In-air annealing instead shows a recovery of the laser damage threshold.