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题名	薄膜态材料空间辐照效应研究
作者	崔岩岩
学位类别	硕士
答辩日期	2016
授予单位	中国科学院上海光学精密机械研究所
导师	齐红基
关键词	Gamma射线 空间辐照 疲劳效应 光学薄膜
其他题名	Space irradiation effect of optical coatings
中文摘要	薄膜元件是各类激光器系统的核心器件，激光系统的输出特性与薄膜元件性能密切相关。与实验室环境或者地面使用环境不同，在空间运行的激光系统面临着真空环境、热循环、太阳照射、粒子辐照、原子氧、有机物污染等复杂工作环境。作为激光系统中的关键部件，光学薄膜元件通常是极易损坏的薄弱环节，需要研究空间环境下薄膜元件的性能变化情况，为空间激光系统薄膜元件的选择及激光系统性能评估提供依据。本文针对空间环境下运行激光系统中薄膜元件面临的Gamma射线辐照和多脉冲激光辐照这两个因素对光学薄膜元件性能影响进行了地面模拟实验和结果分析。论文主要内容如下： 首先介绍了本文相关实验所用样品制备设备、薄膜样品测试分析仪器和性能测试分析方法。 研究了多脉冲纳秒激光辐照下多层反射薄膜的损伤特性变化，结果表明随着激光辐照次数的增加，反射薄膜元件表现出疲劳效应，但当辐照次数达到一定水平之后，疲劳效应趋于饱和。运用改善的缺陷统计模型，研究了多脉冲作用下高反薄膜内部缺陷演化过程。在缺陷拟合模型中，以高低折射率膜层为基本单元，考虑了多层薄膜驻波场对缺陷统计模型影响，较为准确获得高低折射率膜层单元内部缺陷密度分布情况，定量分析了多脉冲作用下缺陷演变规律，较好地解释了激光诱导高反膜损伤阈值降低及饱和效应。 设计并实施了Gamma射线辐照模拟实验，针对熔石英空白基底、HfO2单层膜、TiO2单层膜分别进行了不同剂量的Gamma射线辐照实验。分别测量了辐照前后样品的光学性质、表面、结构与成分变化情况。结果显示，对于熔石英基底，Gamma射线辐照后，折射率基本无变化，但熔石英基底在短波段存在由材料吸收引起的透过率下降情况。对于HfO2及TiO2单层膜，Gamma射线辐照后透过率在短波段也发生明显下降，单辐照前后样品的粗糙度无有明显变化。对HfO2单层膜，分析还发现辐照使其致密化，但带隙没有发生明显变化。此外，不同的辐照条件对样品的原子结合能与元素化学计量比、结晶状况影响程度不同。
英文摘要	Optical coatings are key components for laser systems operating in the space environment, which limit the output power and operating stability seriously. Differing from laboratory or terrestrial environment, the coatings are exposed to a very complex environment, including vacuum, thermal cycling, solar radiation, particle radiation, atomic oxygen, pollution and other complex effects. In this paper, the ground simulations about the Gamma ray irradiation and multiple laser irradiations were carried out to solve the influence of failure for optical films on space laser systems and even spacecraft. It includes the following sections. The equipments used for environment simulation and testing samples were introduced, as well as the methods of test and analysis. The defect evolution is investigated for the high-reflective coatings under multiple irradiation with the improved statistical model. The fatigue effect is observed with increasing the shot numbers but the fatigue process will not endure and it tends to be saturated when number of shots reaches some level. With the assumption of bilayer unit, the defect density distribution of the high-reflective coatings is obtained. Two defect types are identified and the differentiation of the high damage precursors can well explain the decrease of the laser induced damage threshold as well as the saturation effect. The Gamma ray irradiations were designed and implemented. The bared fused silica substrate, HfO2 monolayer coating and TiO2 monolayer coating were irradiated by Gamma ray with different doses. Before and after irradiation, spectrum, roughness, X-Ray diffraction pattern and X-ray photoelectron spectroscopy were measured. The results suggest that for fused silica substrate the refractive index stay all the same after Gamma ray irradiation. But the transmittance is declined at short wavelength, which is caused by the change of absorbance. For HfO2 monolayer coating and TiO2 monolayer coating, the transmittance is also declined at short wavelength and the roughness has no obvious change before and after Gamma ray irradiation. Gamma ray irradiation also bring densification in HfO2 monolayer coating and the band gap didn't change obviously. The binding energy, the ratio of elements and the crystallization of coatings are also changed before and after Gamma ray irradiation.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16997]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	崔岩岩. 薄膜态材料空间辐照效应研究[D]. 中国科学院上海光学精密机械研究所. 2016.

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