大口径透镜色差对多程结构钕玻璃拍瓦激光聚焦时空特性的影响
Influence of Chromatic Aberration of Large Aperture Lens on Focusing Spatiotemporal Characteristics in Multi-Pass Nd∶Glass Petawatt Laser
李佳美 1李大为 2王韬 3余惠 1徐光 2王利 2卢兴强2
作者信息
- 1. 中国科学院上海光学精密机械研究所高功率激光物理联合实验室,上海 201800;中国科学院大学材料与光电研究中心,北京 100049
- 2. 中国科学院上海光学精密机械研究所高功率激光物理联合实验室,上海 201800
- 3. 中国工程物理研究院上海激光等离子体研究所,上海 201800
- 折叠
摘要
本文基于宽频带激光在透镜中的衍射传输理论,针对国内多程放大结构的高能拍瓦激光系统设计,研究了大口径透镜导致的脉冲时间延迟(PTD)对宽频带激光焦斑时空特性的影响.研究发现,当宽带激光口径达到360 mm×360 mm时,透镜导致的最大PTD约为2.5 ps,当在3.2 nm的傅里叶变换极限带宽下脉冲宽度为0.5 ps和光束质量为1倍衍射极限(DL)时,聚焦过程时空耦合效应最强,时间波形发生畸变的同时,90%的能量集中度对应的焦斑尺寸也将增加一倍;但当压缩脉冲宽度在≥1 ps或远场光束质量不小于5倍 DL时,焦斑的时空耦合效应变弱,PTD带来的影响可以忽略.该研究结果将为国内高能拍瓦激光系统的透镜色差补偿和聚焦性能提升提供重要的理论依据.
Abstract
The influence of pulse time delay(PTD)caused by the large-diameter lens on the spatiotemporal characteristics of a broadband laser focal spot is studied to design a high-energy laser system.To this end,diffraction transmission theory of broadband lasers in lenses,which is used in high-energy petawatt laser system with multi-pass amplified structure,is employed.It is found that when the aperture of the broadband laser reaches 360 mm×360 mm,the maximum PTD caused by the lens is approximately 2.5 ps.The spatiotemporal coupling effect peaks when the pulse width is 0.5 ps under the Fourier-transform-limit bandwidth of 3.2 nm and the beam quality is 1 diffraction-limited(DL).The time waveform is distorted,and the focal spot size corresponding to 90%energy concentration is doubled.However,when the compressed pulse width is more than 1 ps or the far-field beam quality is≥5 DL,the spatiotemporal coupling effect weakens,and the influence of the PTD on focus can be neglected.The research results provide an important theoretical basis for the lens chromatic aberration compensation and fosus performance improvement of domestic high-energy petawatt laser systems.
关键词
超快光学/透镜色差/脉冲时间延迟/多程放大结构/焦斑时空特性/高能拍瓦激光系统Key words
ultrafast optics/lens chromatic aberration/pulse time delay/multi-pass amplified structure/spatiotemporal characteristics of focal spot/high-energy petawatt laser system引用本文复制引用
基金项目
中国科学院国际合作局对外合作重点项目(181231KYSB20170022)
出版年
2024
NETL
NSTL
万方数据