纳秒脉冲激光对多层介质膜光栅的损伤机理及激光预处理研究
文献类型：学位论文
| 作者 | 高鹏鹏 |
| 学位类别 | 硕士 |
| 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 | 晋云霞 |
| 关键词 | 多层介质膜光栅 激光损伤阈值 损伤形貌 激光预处理 |
| 其他题名 | Ns Pulsed Laser Induced Damage Mechanisms and Laser Conditioning Techniques of Multilayer Dielectric Grating |
| 中文摘要 | 多层介质膜光栅（MDG）由于具有接近100%的高衍射效率及相对于金属光栅更高的抗激光损伤特性成为脉冲压缩光栅研究的重要方向，但是抗激光损伤能力仍是制约其性能进一步提高的重要因素，因此研究其在短脉冲激光作用下的损伤机理和提高其激光损伤阈值（LIDT）显得尤为重要。本文在分析ns脉冲激光作用下多层光栅膜和MDG的损伤特性的基础上，着重探索了MDG的激光预处理工艺。 首先，介绍了MDG损伤实验测试平台及损伤实验操作，通过对MDG制备工艺流程的操作实践和对MDG损伤形貌显微观察，确定了ns脉冲作用下光栅结构内杂质和微结构缺陷是引起MDG损伤的主要因素。 其次，在小光斑条件下对光栅膜和MDG进行不同光斑尺寸激光损伤阈值测试实验，发现：在ns脉冲条件下MDG同样存在光斑尺寸，即证明了杂质和缺陷密度分布是ns脉冲下影响MDG阈值测试准确性的重要因素；对MDG进行了S-on-1测试发现，MDG的损伤发展性明显强于多层介质膜，这是由其表面光栅结构特点决定的。 最后，在1-on-1和N-on-1实验对比基础上提出并验证了MDG的激光预处理效应。实验表明激光预处理能够有效减少MDG表面光栅结构区的杂质污染和微结构缺陷，激光处理后MDG阈值能提高到处理前的1.5-2倍，同时不损伤顶层光栅结构。在此基础上进行了预处理工艺的探索，并得到阈值明显提高的样品。证明了激光预处理是提高MDG阈值方法的重要补充。 |
| 英文摘要 | Diffraction efficiency of Multilayer Dielectric Grating (MDG) can reach to nearly 100%，and the laser-induced damage threshold (LIDT) of MDG is several times higher than that of metallic grating. Therefore, MDG has become an important topic in the studies of pulse compressor gratings. However, the laser induced damage resistance is still the dominated aspect of the performance of MDGs. So, the research on damage mechanism of MDG and enhancing the LIDT under short pulse laser is particularly important. Based on the analysis of damage characteristics of Multilayer Dielectric (MDL) and MDG under ns pulse laser, the emphasis of this work is focused on the preconditioning technology on MDG: First of all, the damage test platform of MDG and experiment operating methods are introduced. By practicing all the preparation process of MDG and analysing the microstructure damage morphology of MDG, we confirm that the impurities and microstructure defects in top grating structure are the main factors that cause the damage of MDG under ns laser pulses. Secondly, we perform laser damage testing experiments on MDG and MDL with different spot sizes under the condition of small spot aperture. Our experimental results indicate that the effect of spot size on the LIDT of optical thin films is also applicable to MDG with grating structures. Besides, S-on-1 tests on MDG and MDL are presented, which show that the progess of laser induced damage of MDG is clearly stronger than that of MDL. Finally, the laser conditioning effect is proposed and confirmed based on the comparison of the 1-on-1 and N-on-1 test results with the same spot zize. Using the mode of raster scanning over the entire aperture of experimental samples we carry out the laser-conditioning test and obtain the MDG samples with higher LIDT. Significantly, laser-conditioning could be an alternative way to improve the LIDT of MDG. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16692]  |
| 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 | 高鹏鹏. 纳秒脉冲激光对多层介质膜光栅的损伤机理及激光预处理研究[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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