Author Affiliations
Abstract
1 Thales LAS France, 78990Élancourt, France
2 Thales Systems Romania, 060071Bucuresti, Romania
3 Extreme Light Infrastructure - Nuclear Physics, IFIN-HH, 077125Magurele, Romania
4 Physics Doctoral School, Bucharest University, 077125Magurele, Romania
5 Laser Engineering, Osaka University, Osaka565-0871, Japan
We report on the generation and delivery of 10.2 PW peak power laser pulses, using the High Power Laser System at the Extreme Laser Infrastructure – Nuclear Physics facility. In this work we demonstrate for the first time, to the best of our knowledge, the compression and propagation of full energy, full aperture, laser pulses that reach a power level of more than 10 PW.
high-power laser ultra-short laser pulses High Power Laser Science and Engineering
2022, 10(3): 03000e21
Author Affiliations
Abstract
1 Thales LAS France, 78990Élancourt, France
2 Thales Systems Romania, 060071București, Romania
3 Extreme Light Infrastructure – Nuclear Physics, ‘Horia Hulubei’ National Institute for Physics and Nuclear Engineering, 077125Bucharest Magurele, Romania
4 University of Bucharest, Faculty of Physics, 077125Bucharest Magurele, Romania
We report on a two-arm hybrid high-power laser system (HPLS) able to deliver 2 × 10 PW femtosecond pulses, developed at the Bucharest-Magurele Extreme Light Infrastructure Nuclear Physics (ELI-NP) Facility. A hybrid front-end (FE) based on a Ti:sapphire chirped pulse amplifier and a picosecond optical parametric chirped pulse amplifier based on beta barium borate (BBO) crystals, with a cross-polarized wave (XPW) filter in between, has been developed. It delivers 10 mJ laser pulses, at 10 Hz repetition rate, with more than 70 nm spectral bandwidth and high-intensity contrast, in the range of 1013:1. The high-energy Ti:sapphire amplifier stages of both arms were seeded from this common FE. The final high-energy amplifier, equipped with a 200 mm diameter Ti:sapphire crystal, has been pumped by six 100 J nanosecond frequency doubled Nd:glass lasers, at 1 pulse/min repetition rate. More than 300 J output pulse energy has been obtained by pumping with only 80% of the whole 600 J available pump energy. The compressor has a transmission efficiency of 74% and an output pulse duration of 22.7 fs was measured, thus demonstrating that the dual-arm HPLS has the capacity to generate 10 PW peak power femtosecond pulses. The reported results represent the cornerstone of the ELI-NP 2 × 10 PW femtosecond laser facility, devoted to fundamental and applied nuclear physics research.
lasers high-power laser pulses ultra-short laser pulses High Power Laser Science and Engineering
2020, 8(4): 04000e43
强激光与粒子束
2020, 32(9): 092002
红外热波检测技术被应用于零部件或设备内部缺陷及故障的检测与定量识别。本文建立了半无限材料中圆柱绝热缺陷在超短激光脉冲辐照下的非傅里叶热传导波动模型, 在采用波函数展开法和镜像法研究热波散射正问题的基础上, 运用遗传算法对亚表面缺陷深度进行反演, 实际测量温度取热波散射正问题计算得到的材料表面温度, 并且分析讨论了测温点数目、入射频率等因素对反演结果的影响。数值实验结果证明了该方法的有效性。与 L-M法和共轭梯度法相比, 该方法在反演的精度及速度上都有较为良好的表现。
超短激光脉冲 非傅里叶热传导 导热反问题 遗传算法 ultra-short laser pulse, Non- Fourier law, inverse
1 中国科学院 长春光学精密机械与物理研究所, 吉林 长春 130033
2 中国科学院大学, 北京 100039
为研究双温方程中电子热传导项和电子与晶格耦合项对激光辐照物体表面温度场求解的影响, 对这两项施加了约束条件。由于飞秒和亚皮秒激光与物质相互作用时间短, 电子与晶格来不及耦合, 所以对耦合项施加时间约束; 根据相分离条件(CPPS), 对热传导项施加空间约束。利用有限元方法建立了激光烧蚀金属铜膜表面的有限元模型。通过分析双温方程中热传导项和耦合项对计算结果的影响, 发现短脉冲激光与铜金属相互作用过程中电子与晶格耦合项可以忽略, 而传导项不可忽略。求解适当激光功率下的双温方程, 得到了激光作用中心电子与晶格在不同脉冲宽度激光辐照下的温度变化关系。根据100 fs激光作用后晶格温度场的空间分布情况, 研究了激光作用的相分离区域、相爆炸区域以及熔融区域的分布情况。
短脉冲激光 双温方程 有限元 相分离(CPPS) ultra-short laser pulse two temperature model (TTM) finite element method (FEM) critical-point phase separation(CPPS)
为了研究超短激光脉冲光束质量对焦斑的影响, 采用经典的几何模型进行了理论模拟分析, 并实验研究了离轴90°抛物面镜的飞秒激光光束的紧聚焦特性。由理论分析和实验结果可知, 当入射失准角为3mrad时, 将从空间上使焦斑峰值功率密度减半, 失准角的存在将引起到达靶面的激光脉冲的时间展宽从而降低焦斑峰值功率密度; 利用3TW钛宝石飞秒激光系统, 通过f/1离轴90°抛物面镜对激光束进行紧聚焦, 得到最佳焦斑尺寸为5.6μm×5.4μm, 对应于3mJ和96mJ的飞秒脉冲激光光束的焦斑峰值功率密度分别为3.83×1017W/cm2和1.23×1019W/cm2。结果表明, 该研究为开展激光与固体、气体、团簇等物质相互作用的相关实验提供了重要的参考。
激光光学 峰值功率密度 超短激光脉冲紧聚焦 离轴抛物面镜 laser optics peak power density focal spot of ultra-short laser pulse off-axis parabolic mirror
在能量11 mJ、波长744 nm、脉宽120 fs、功率密度6×1016 W/cm2的超短脉冲装置上，开展了超短脉冲激光与2.1 μm和5.0 μm金薄膜靶相互作用产生质子束的实验研究。利用Thomson谱仪测量了产生的质子能谱，发现利用2.1 μm金薄膜靶时，质子能谱由于质子源数量不足而在74 keV附近出现单能峰，5.0 μm的金薄膜靶产生的质子计数和能谱均比2.1 μm的金薄膜靶产生的低，主要原因是超热电子穿过薄膜靶时出现的能量损失和几何倾斜降低了电子回流所致。interaction with thin gold foils
超短激光 薄膜靶 质子加速 能谱 ultra-short laser thin foil proton acceleration energy spectrum
中国工程物理研究院 激光聚变研究中心, 等离子体物理重点实验室， 四川 绵阳 621900
在采用啁啾脉冲放大技术的高功率短脉冲激光装置中，终端衍射光栅的损伤阈值是限制装置输出能力的瓶颈之一。提出了测量大口径光栅损伤阈值的方法。该方法通过在线监测采集大口径光斑的同发近场光强分布情况和相应的光栅损伤图像，并经过一系列后期图像数据处理，建立起能量与损伤点的对应关系，经过一个测试光斑便可获得所有通量下的光栅损伤特性。该测量方法对光斑均匀性没有硬性要求，为损伤测量装置中难以解决的光斑均匀性问题提出了新的应对思路和方法。
激光损伤阈值 大口径衍射光栅 超短激光脉冲 图像处理 laser induced damage large-aperture diffraction grating ultra-short laser pulse image processing
