重复频率激光作用下的光学薄膜损伤
文献类型：学位论文
| 作者 | 张东 |
| 学位类别 | 硕士 |
| 答辩日期 | 2009 |
| 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 |
| 关键词 | 光学薄膜 重复频率 S-on-1 脉冲激光 激光损伤 损伤概率 |
| 其他题名 | Repetitive frequency laser induced damage of optical coatings |
| 中文摘要 | 本文在消化吸收国际标准ISO11254-2的基础上，结合我们的实际条件，建立了一套标准的S-on-1激光损伤测试规范，为科学、客观、深入研究光学薄膜的重复频率激光损伤现象及其损伤机理奠定了基础。本论文将损伤形貌也作为评价光学薄膜抗重复频率激光损伤特性的一个因素，将ISO11254-2统计损伤的两个变量（脉冲能量和脉冲次数）转化到了两个新的变量（脉冲能量和损伤状态）上，从而形成了一种新的激光损伤评价方法。 以激光与薄膜相互作用机制为理论依据，运用在热力耦合破坏理论的基础上建立的多层膜温度场模型和界面吸附模型以及把缺陷作为导致薄膜损伤主要因素建立的缺陷吸收损伤模型，对典型激光薄膜的在重复频率（S-on-1）激光作用下的损伤行为进行了实验研究，剖析了光学薄膜的重复频率激光损伤机制。重点研究了光学薄膜在低重复率激光（5Hz）作用下的累积效应的现象，研究表明累积效应在不同材料之间具有很大差异性。为了进一步分析损伤机制，研究了重复频率激光预处理对光学薄膜吸收的影响。 我们将损伤形貌区分为两种：弱损伤与强损伤。以固定数目的激光脉冲辐照测试点，由每个测试点点的损伤状态（强损伤或弱损伤），计算该能量密度下的弱损伤几率。随着激光能量的增加，弱损伤几率曲线呈现先增加后减小的趋势，并且会出现一个峰值。该峰值所对应的激光能量密度具有较好的重复性，故可作为光学薄膜重复激光损伤特性的评价方法。需要说明的是，弱损伤几率峰值所对应的激光能量密度与采用国际标准ISO11254-2所测量出的零几率损伤阈值在本质上是不同的。零几率损伤阈值是损伤从无到有的转变点，而弱损伤几率峰值所对应的激光能量密度是损伤由弱到强的转变点。经过分析，该转变点与功能损伤阈值的本质是一致的。然而，转变点的标准的选取和优化还要进一步的研究。 |
| 英文摘要 | On the basis of international standard ISO11254-2 and the actual conditions of our laboratory, a standard norm of S-on-1 laser damage test has been established in this article, which lay a foundation for the scientific, objective and in-depth study of the repetitive frequency laser damage phenomena and mechanism of optical coatings. By adding morphology of the damage into evaluation of optical coatings，we transform the two variables (pulse energy and pulse frequency) defined by ISO11254-2 into two new variables (pulse energy, and injury status) to form a new evaluation method of repetitive frequency laser-induced damage. The damage behaviors of several typical optical coatings used in repetitive frequency (S-on-1) laser system were investigated under the experimental research by the temperature field model and interface absorption layers model as well as the defect induced laser damage model. The repetitive frequency laser damage mechanism of optical coatings was also analyzed. A study focus on the cumulative phenomenon of optical coatings under the influence of low repetitive frequency (5Hz) laser and the study reveals that coatings of different materials show a large difference in the cumulative effect. In order to further reveal the damage mechanisms of repetitive frequency laser the influence of repetitive frequency laser pre-conditioning on the absorption of optical coatings was also investigated. Damage states were divided into two kinds: slight damage and severe damage. Every test point was irradiated by a fixed number of laser pulses, which gives the damage state (slight damage and severe damage) of every test point. The damage probability of slight damage at every energy density was calculated. As the laser energy increases, the probability curve of slight damage increases first and then decreases, and there will be a peak. The laser energy density at this peak has so good repeatability that it can be used as evaluation of repetitive frequency laser resistance of optical coatings. It should be noted that the laser energy density at this peak is different from zero probability LIDT achieved by ISO11254-2 measurements. Zero probability LIDT is the transition point from no damage to damage, and the laser energy density at this peak is the transition point from slight damage to severe damage, it has the same nature with the functional damage threshold (FDT). However, the selection criteria of the transition point needs to be further studied and optimized. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16420]  |
| 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 | 张东. 重复频率激光作用下的光学薄膜损伤[D]. 中国科学院上海光学精密机械研究所. 2009. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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