Using ion post-treatment technique to improve laser-induced damage threshold of thin films

ZrO2 thin films were deposited on K9 glass substrates by e-beam evaporation method and some samples were treated with low energy O+2 after deposition. Surface weak absorption was measured using surface thermal lens technique, and micro-defect density was measured using optical microscope. The experimental results indicate that the absorption of the samples decreases from 1.147×10-4 to 9.56×10-5 after post-treatment, and the micro-defect density reduces from 18.6/mm2 to 6.2/mm2 compared with the un-treated samples. Anti-laser-irradiation test indicates that the laser-induced damage threshold are improved from 15.9 J/cm2 to 23.1 J/cm2 comparing the ion-post treatment samples with the untreated samples. By analysis of the defect density, weak absorption, and damage morphologies of the sampl