应用离子后处理技术提高薄膜激光损伤阈值

利用电子束热蒸发方法在K9玻璃基底上沉积氧化锆薄膜，并对其中一些样品用低能O2+进行了后处理。采用表面热透镜技术测量薄膜样品表面弱吸收，采用显微镜观察样品离子后处理前后的显微缺陷密度。测试结果表明:经离子后处理样品表面的缺陷密度从18.6/mm2降低到6.2/mm2，且其激光损伤阈值从15.9 J/cm2提高到23.1 J/cm2，样品的平均吸收率从处理前的1.147×10-4降低到处理后的9.56×10-5。通过对处理前后样品的表面微缺陷密度、吸收率及损伤形貌等的分析发现:离子后处理可以降低薄膜的显微缺陷和亚显微缺陷，从而降低薄膜的平均吸收率，同时增强了薄膜与基底的结合力，提高了薄膜的激光损伤阈值。

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~+1 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/mm~2 to 6.2/mm~2 compared with the un-treated samples. Anti-laser-irradiation test indicates that the laser-induced damage threshold are improved from 15.9 J/cm~2 to 23.1 J/cm~2 comparing the ion-post treatment samples with the untreated samples. By analysis of the defect density, weak absorption, and damage morphologies of the samples, it is found that the reduction of the micro-defect and sub-micro-defect density after ion treatment, so the reduction of the average absorption, and the enhancing of the adhesion of films and substrates are the main reasons that the laser -induced damage shreshold of the films increase.