超快动力学过程诊断技术的研究与应用
文献类型：学位论文
| 作者 | 杨明 |
| 学位类别 | 硕士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 刘建胜 |
| 关键词 | 线性啁啾激光 超快动力学诊断 团簇尺寸 高速检测 |
| 其他题名 | Study and Application on Characterization of Ultrafast Dynamics Process |
| 中文摘要 | 随着超短超强激光技术的迅猛发展，目前在小型化台式激光系统上，时间宽度小于10fs的超短脉冲激光已经得以实现了，在可聚焦功率密度方面也已经达到了~1020W/cm2量级，这为众多学科领域提供了前所未有的实验手段和极端实验条件。 这种极端条件为我们研究原子分子结构与机理带来了新的研究机遇，同时也对我们目前的测量手段提出更高的要求，尤其在对原子的电离过程、等离子体中电子密度的演化、冲击波的发展过程、激光引起物质结构的变化等的研究中，由于作用时间通常为数百飞秒甚至阿秒量级，因此能够对这些超快动力学过程的进行高时间分辨率的诊断显得至关重要。 本论文取得的主要成果如下： 1.采用线性啁啾脉冲激光作为探针，建立了一套超快动力学诊断测量系统。利用光谱仪测量团簇膨胀过程中的散射光，可以研究团簇在激光场中的膨胀动力学过程。测量了不同背压和延迟时间下团簇散射光的红移量，并据此判断所产生的团簇尺寸的相对大小。根据我们的实验结果，对瑞利散射法的结果进行了讨论。 2.在团簇尺寸测量过程中，观察到了低密度大尺寸的团簇源。在1bar背压的情况下得到了比以往40bars背压下产生的尺寸更大的团簇。同时团簇密度很低。这可以在未来的实验中作为重要的团簇源。 3.采用线性啁啾脉冲激光作为探针，设计了一套高频信号脉冲序列检测系统，在理论上分析了测量的时间分辨率.这种检测系统可以在未来的实验以及其他应用中用以检测高速光脉冲信号。 |
| 英文摘要 | With the tremendous progress of ultra fast and ultra intense laser technology, laser pulses with a duration of shorter than 10fs and laser intensity on the 1020W/cm2 scale have been available on a compact table-top system. These have offered novel experimental methods and created extreme physical conditions in various research field. The extreme condition brought us opportunities of understanding the structure of atoms and molecules as well as new challenge to the detecting system. The high resolution diagnosis of ultrafast dynamic process is most important, especially during the process of atom’s ionization, evolution of electron’s density in plasma, develop process of shocking wave, and structure change of matter irradiated by laser.. Main results are given as follows: 1. Employing a linearly chirped laser pulse, a measure system for ultrafast dynamical process is built. 90°side scattering light of expanding clusters is collected and recorded by a spectrometer, and used to investigate the expanding process of the clusters in laser. Red-shift of scattering light by clusters generated under different backing pressure and different delay time is measured, based on which the comparative size of clusters is investigated. The result made with Rayleigh Scattering is discussed. 2. Low density and large size clusters are observed in our experiment. The size of clusters generated under 1bar could be larger than generated under 40bars before, while the density is very low. It could act as an important cluster source in the future. 3. Using linearly chirped laser pulse, a measure system for high speed pulse train is designed. The time resolution of the measurement is analyzed theoretically. The system could be used to detect high speed pulses in the future experiments and other fields. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16531]  |
| 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 | 杨明. 超快动力学过程诊断技术的研究与应用[D]. 中国科学院上海光学精密机械研究所. 2007. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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