基于预植缺陷的纳秒脉冲激光诱导薄膜损伤研究
文献类型：学位论文
| 作者 | 单永光 |
| 学位类别 | 博士 |
| 答辩日期 | 2011 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 贺洪波 ; 魏朝阳 |
| 关键词 | 光学薄膜，节瘤缺陷，纳米吸收缺陷，激光诱导损伤，损伤增长 |
| 其他题名 | Nanosecond Pulsed Laser-induced Damage of Optical Coatings with Artificial Defects |
| 中文摘要 | 光学薄膜是高功率激光系统中必需的重要元件，其抗激光损伤能力往往成为限}!J激光系统向更高功率发展的主要瓶颈。大量激光损伤实验表明:在ns级脉冲范围，薄膜的激光损伤主要是由缺陷引起的。通过深入分析光学薄膜中缺陷的来源、节瘤缺陷的结构特征及损伤特性，可以达到优化薄膜制备工艺、提高薄膜抗激光损伤能力的目的。论文采用人为预植纳米颗粒的方法，较系统地研究了节瘤缺陷的结构特征和损伤特性。采用多种表征技术分析了节瘤缺陷的表面形貌、内部微观结构和损伤形貌;通过实验测试，分析了节瘤缺陷对薄膜损伤I=}J值的影响;采用时域有限差分法((FDTD)模拟了节瘤缺陷所引起的电场增强效应，并分析其对激光损伤过程的影响;基于小球吸收模型和热弹理论，发展和完善了节瘤缺陷的热力藕合损伤模型;采用吸收率不同的纳米颗粒作为预植种子，验证了节瘤种子的尺寸和吸收率对损伤过程的影响。基于温度场理论，采用FDTD方法模拟分析了0,入射条件下1064nm高反膜中常见的平底坑和节瘤坑的场分布情况，很好地解释了平底坑和节瘤坑在后续激光脉冲作用下的损伤增长行为。 通过分析损伤实验结果和损伤形貌，探讨了355nm和1064nm激光对介质高反膜损伤的相同点和不同点;基底亚表面缺陷对增透膜和高反膜损伤的影响。 |
| 英文摘要 | Optical coatings, the vital component of high power laser systems, is still an important bottleneck for further development of high power laser systems, due to the poor capacity of laser damage resistance. Experimental results have indicated that the laser damage of optical coatings is mainly induced by defects in the nanosecond regime. Investigating the seed sources, the characteristics of structure and laser damage of nodular defect, then laser-induced damage threshold (LIDT) of optical coatings can be increased by improving the manufacture process. The characteristics of structure and damage of nodular defect were studied by presetting artificial defect on the substrate to grow nodular defect. The topography, inner structure and damage morphology of nodular defect were characterized by AFM, SEM and FIB. The influence of nodule was investigated on the LIDT of optical coatings by performing laser-induced damage (LID) xperiments. The electric-field enhancement of nodule, simulated by Finite-Difference Time-Domain method (FDTD), and the influence on LID of nodule were studied. Based on the ball absorption model and thermoelastic theory, a thermomechanical model of nodule damage was refined. Investigating the influence of absorptivity and size of odular seed on LID of nodule, artificial defect with different materials and sizes were employed. Based on the theory of temperature field, the behavior of damage growth was well explained by analyzed the electric field distribution, simulated by FDTD, of the flat bottom pit and nodular pit under 00 incident of 1064nin. By performing LID xperiments and comparing damage morphologies, the similarities or differences of LID of dielectric coatings are studied between 355nm and 1064nm. And the influence of defects originating from subsurface of substrate is analyzed on the LID of high reflective (HR) and anti-reflective (AR) coatings. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15814]  |
| 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 | 单永光. 基于预植缺陷的纳秒脉冲激光诱导薄膜损伤研究[D]. 中国科学院上海光学精密机械研究所. 2011. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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