Laser-induced damage of 1064 nm multilayer antireflection coatings after exposure to gamma rays
Laser-induced damage of 1064 nm multilayer antireflection coatings after exposure to gamma rays
复制标题
1064nm 多层减反射涂层暴露于伽马射线后激光引起的损伤
DOI：
10.1016/j.optmat.2021.111580
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发表时间：
2021-12-06
影响因子：
3.9
通讯作者：
Shao, Jianda
中科院分区：
文献类型：
--
作者：
Wang, Zhihao;Wang, Yanzhi;Shao, Jianda
为空间应用而设计的激光涂层不仅会遇到恶劣的空间环境，而且会遭受激光辐照。空间中的高能辐射，如γ射线，会对材料造成缺陷和其他损伤，这可能有助于由缺陷吸收引起的激光损伤。本文研究了三组1064 nm多层增透膜在345戈伊γ射线辐照下的光学特性和结构组成，以及γ射线辐照对薄膜激光损伤特性的影响。实验结果表明，经γ射线辐照后，增透膜的吸收率和表面粗糙度增加，透过率降低。X射线光电子能谱（XPS）分析证实，SiO2是更脆弱的γ辐射下相比，Ta2O5和HfO2。抗反射涂层的γ射线损伤主要发生在SiO2层，由氧空位和带电缺陷的产生组成。γ射线产生的缺陷增加了薄膜对激光功率的吸收，从而增加了薄膜的激光损伤概率，降低了薄膜的激光损伤阈值。与电子束蒸发涂层相比，溅射沉积技术制备的涂层显示出较低的概率由γ射线辐射损伤。
Laser coatings designed for space applications not only encounter harsh space environments, but also suffer from laser irradiation. High-energy radiation in space, such as Gamma rays, can cause defects and other damage to materials, which could contribute to laser damage induced by defect absorption. In this work, we studied the optical properties and structural composition of three groups of 1064 nm multilayer antireflection (AR) coatings irradiated by Gamma rays (345 Gy), and the effect of Gamma ray radiation on the laser-induced damage properties of thin films. Experimental results revealed that after exposure to Gamma ray, the absorption and surface roughness of the AR coating increased while the transmittance decreased. X-ray photoelectron spectroscopy (XPS) analysis confirmed that SiO2 is more fragile under Gamma radiation compared to Ta2O5 and HfO2. It was also demonstrated that the Gamma ray damage of AR coatings mainly occurred in the SiO2 layers, and consist of generation of oxygen vacancies and charging defects. The defects generated by Gamma rays increased the absorption of the laser power by the film, hence increasing the probability of laser-induced damage and reducing the laser-induced damage threshold of the film. The coatings prepared by sputtering deposition technique showed lower probability of damage by Gamma ray radiation compared to electron-beam evaporated coatings.