飞秒拍瓦级激光器波前逐级测量和分析
文献类型：学位论文
| 作者 | 刘美标 |
| 学位类别 | 硕士 |
| 答辩日期 | 2010 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 梁晓燕 |
| 关键词 | 波前测量 波前校正 自适应光学 波前传感器 飞秒拍瓦级激光系统 |
| 其他题名 | Wavefront measurement and analysis of the femtosecond petawatt-level Ti:sapphire laser system |
| 中文摘要 | 超短脉冲高功率激光系统可以为许多实验提供极端的物理条件，通过自适应光学技术校正波前可使聚焦功率密度提高，从而满足高量级物理实验的需求。本文简要介绍了波前校正技术的发展及其在众多领域的应用，特别是波前校正技术在高功率激光器中的应用。还介绍了光束波前的测量方法，各种方法的基本原理和优缺点，及自适应光学波前校正技术的基本原理。 为了更好的校正激光脉冲的波前畸变，我们逐级测量了飞秒拍瓦级激光系统的波前，了解光束在放大和压缩过程中波前的演变特性，分析了波前畸变的主要起因和波前畸变对聚焦光斑的影响。 主要研究成果如下： 1. 对飞秒拍瓦级激光系统的波前进行了逐级测量，这样可以了解飞秒拍瓦级激光系统波前畸变的逐级变化过程。并且为了研究动态波前校正，测量了飞秒拍瓦级激光系统五程前置放大器不同泵浦光能量时的波前畸变规律。结果表明经过多通放大的激光脉冲，由于热透镜效应，激光脉冲波前不仅离焦量(Defocus)发生了变化，像散量(0° Astigmatism)也发生了变化。 2. 测量了飞秒拍瓦级激光系统重复频率为单次时的波前畸变，得到了单次时波前的相位图，并与10Hz条件下的波前测量结果比较。结果表明当功率放大器泵浦能量约为3J而终端放大器泵浦能量约为12J时，靶室中单次时的波前相比较10Hz的光的波前没有明显变化。 3. 应用自适应光学系统对飞秒拍瓦级激光系统的波前进行了初步校正，给出了波前校正前和波前校正后的焦斑。比较焦斑表明自适应光学系统可以在我室飞秒拍瓦级激光系统正常工作。 |
| 英文摘要 | The development of ultrashort high power laser system is valuable for a variety of high-field appliction. The seeking for more powerfull laser has never ceased, adaptive optics is used as a wavefront correction technique to increase the focal peak intensity of ultrashort high power laser system. With use of the adaptive optics, the focus spot of laser system can become smaller so that higher amplitude electric field come true. The development and appliction of the wavefont correction technique are introduced and the appliction of the wavefont correction technique in ultrashort high power laser system is introduced detailedly. A variety of methods of measuring wavefront and the merit and demerit of different wavefront measuring methods are also disscussed. The principle of adaptive optics are introduced. In order to better correction of the wavefront of the laser system, the output laser pusle’s wavefront of every amplifier stage of the laser system is measured. The reason of the abberation and the relation between the wavefront abberation and the focus spot are shown. The main results in the thesis can be summarized as follows: 1. The wavefront of several amplifier stage of the laser system is measured, so the evolution of abberation of the femtosecond petawatt-level laser system can be shown. Furthermore, in order to correct the wavefront real time, the relation between the wavefront and the pump energy of the five pass pre-amplifier is demonstrated. Further analyses demonstrate that the defocus and the 0° astigmatism increase with pump energy owing to the thermal lensing effect. 2. The wavefront of the femtosecond petawatt-level laser system in the target chamber when the system works in shot mode is shown. The results show that the wavefront of single shot compare to of 10Hz changes little when the pump energy of power amplifier and final amplifier are 3J and 12J separately. 3. The adaptive optic system have been used to correct the wavefront of the femtosecond petawatt-level laser system. The focus spot before and after correction are demonstrated and it shows that the wavefront correction system can work properly |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16675]  |
| 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 | 刘美标. 飞秒拍瓦级激光器波前逐级测量和分析[D]. 中国科学院上海光学精密机械研究所. 2010. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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