Author Affiliations
Abstract
1 Institute of Advanced Science Facilities, Shenzhen, China
2 College of Science, Southern University of Science and Technology, Shenzhen, China
3 Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, China
4 State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
The development of high-brightness X-ray free electron lasers (XFELs), such as hard X-ray self-seeding free electron lasers and XFEL oscillators (XFELOs), brings a severe challenge to the crystal monochromator due to a strong non-uniform thermal load. The distortion caused by spatial temperature gradients can severely affect the optical performance of crystals. Therefore, this paper presents a model to estimate the performance of non-uniform thermally distorted crystals. The model not only takes into account thermal strain, slope error and incident angle deviation, but also considers temperature-dependent factors such as the Debye–Waller factor and electric susceptibility. Our investigation indicates that the Debye–Waller factor reduces the height and bandwidth of rocking curves, and the impact of the electric susceptibility is tiny. The proposed model can describe the distortion of the reflectivity and transmissivity curves of non-uniform thermally loaded crystals and can be applied in the design of crystal monochromators, crystal splitters, crystal compressors and XFELOs.
crystal monochromator free electron laser thermal load X-ray diffraction High Power Laser Science and Engineering
2023, 11(6): 06000e69
1 深圳综合粒子设施研究院，广东 深圳 518107
2 中国科学院 大连化学物理研究所，辽宁 大连 116023
深圳中能高重频X射线自由电子激光（S3FEL）将建设成为全球唯一软X射线波段的高重频自由电子激光。废束桶是S3FEL装置的重要设备，在系统调束中发挥着重要作用。废束桶束窗是废束桶的重要组成部件，用于隔离和保护加速器超高真空环境。本文对几种常用的废束桶束窗材料进行了对比分析，最终选择铍作为束窗的材料，并依此设计了一种带有水冷结构的束窗。通过蒙特卡罗方法计算得到不同厚度束窗的沉积功率，采用有限元分析方法对不同厚度的束窗进行热结构计算与分析，得到厚度为1.6 mm的水冷铍窗效果最佳，其最大温度为121.6 ℃，低真空为1 Pa时的最大应力与中心变形分别为198.7 MPa和0.00082 mm，低真空为101325 Pa时的最大应力与中心变形分别为204.2 MPa和0.097 mm，结果均满足使用要求。此研究为S3FEL的废束桶束窗设计提供了重要的理论依据。
自由电子激光 高重频 废束桶 束窗 有限元分析 free electron laser high repetition frequency dump beam window finite element analysis 强激光与粒子束
2023, 35(3): 034001
1 高功率激光物理联合实验室, 上海 201800
2 中国科学院上海光学精密机械研究所, 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
神光Ⅱ大型固体高功率激光装置是我国激光驱动器发展历史的里程碑, 其成功研制使我国高功率固体激光工程与技术、聚变物理与基础物理研究实现了全面且本质的跨越式发展。简要概述了神光Ⅱ激光装置研制中创新发展的大量工程方案与技术手段, 举例介绍了神光Ⅱ激光装置在近20年来的高质量运行中取得的众多有国际影响力的研究成果。经多方支持和多年持续发展, 已经形成数万焦耳级纳秒激光装置、皮秒拍瓦以及飞秒拍瓦激光装置等, 这些装置是我国惯性约束核聚变、强场物理、高能量密度物理等研究领域中重要的物理实验核心平台之一。
激光技术 惯性约束核聚变 固体激光驱动器 聚变点火 高功率激光
天津大学精密仪器与光电子工程学院 光电信息技术科学教育部重点实验室, 天津 300072
结合Er/Yb共掺双包层光纤(EYDCF)和主振荡功率放大(MOPA)技术,采用高功率多模抽运方式设计和实验研究了全光纤化两级放大器。分析了放大器的各种性能参数; 1550 nm连续光放大得到最大斜率效率为29%,最大输出功率1.52 W, 功率稳定度0.4％;2 kHz脉冲放大时得到最大输出功率1.1 W,功率稳定度0.45％, 最大斜率效率25%。并从放大后光谱和时域波形分析了导致脉冲放大时斜率效率和功率转换效率较低的主要原因为Yb3+离子波段放大自发辐射(ASE)的出现和Er离子波段ASE的过多积累。在高功率放大时, 增益随输入信号功率增大迅速下降; 同时结合抽运光频谱随驱动电流变化分析了其对放大器性能的影响。
激光技术 光纤放大器 主振荡功率放大 Er/Yb共掺双包层光纤
Author Affiliations
Abstract
1 高功率激光物理国家实验室,中国科学院上海光学精密机械研究所,上海,201800
2 高功率激光物理国家实验室,上海激光等离子体研究所,上海,201800
3 中国工程物理研究院激光聚变研究中心,四川,绵阳,621900
4 上海激光等离子体研究所,上海,201800
Nd∶doped-glass-based sub-picosecond laser system with the maximum peak power of greater than 20 tara watts and the energy on target surface of 16 J is accomplished by using the chirped laser pulse amplification technology. While the laser pulse is focused by an off-axis parabolic mirror, the power density on target surface of approximately 2×10 18 W/cm 2 is acquired. In the performed neutron experiment, a C 8D 8 plate target is placed on the focal spot of the off-axis parabolic mirror. The maximum neutron yield for a single shot reaches 2.4×10 4. Still some other related problems are discussed
惯性约束聚变技术 亚皮秒超短脉冲激光 钕玻璃放大器 中子产额 ICF sub-picosecond ultra short laser pulse Nd∶doped glass based amplifier neutron yield Collection Of theses on high power laser and plasma physics
2003, 1(1): 17
Author Affiliations
Abstract
National Laboratory on High Power Laser and Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
A high power laser system delivering a 20-TW, 0.5 - 0.8 ps ultra-short laser pulse and a 20-J, 500-ps long pulse simultaneously in one shot is completed. This two-beam laser operates at the wavelength of 1053 nm and uses Nd doped glass as the gain media of the main amplification chain. The chirped-pulse amplification (CPA) technology is used to compress the stretched laser pulse. After compression, the ultrashort laser pulse is measured: energy above 16.0 J, S/N contrast ratio ~ 10^(5) : 1, filling factor ~>52.7%. Another long pulse beam is a non-compressed chirped laser pulse, which is measured: energy ~ 20 J, pulse duration 500 ps. The two beams are directed onto the target surface at an angle of 15°.
140.3280 laser amplifiers 190.4970 parametric oscillators and amplifiers Collection Of theses on high power laser and plasma physics
2003, 1(1): 14
1 高功率激光物理国家实验室,中国科学院上海光学精密机械研究所,上海,201800
2 高功率激光物理国家实验室,上海激光等离子体研究所,上海,201800
3 中国工程物理研究院激光聚变研究中心,四川,绵阳,621900
4 上海激光等离子体研究所,上海,201800
利用啁啾脉冲放大技术，建成了一台基于钕玻璃放大器1053 nm波长的亚皮秒超短脉冲激光系统(SPS)。系统的输出峰值功率大于20 TW，靶面最高能量可达16 J，采用离轴抛物面反射镜聚焦，在靶面上获得2×10 18 W/cm 2的激光功率密度，以此激光脉冲轰击氘化聚苯乙烯平面靶，获得单次发射最高2.4×10 4个中子产额。对中子产生的机理进行了相关的讨论。
惯性约束聚变技术 亚皮秒超短脉冲激光 钕玻璃放大器 中子产额
Author Affiliations
Abstract
National Laboratory on High Power Laser and Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
A high power laser system delivering a 20-TW, 0.5 - 0.8 ps ultra-short laser pulse and a 20-J, 500-ps long pulse simultaneously in one shot is completed. This two-beam laser operates at the wavelength of 1053 nm and uses Nd doped glass as the gain media of the main amplification chain. The chirped-pulse amplification (CPA) technology is used to compress the stretched laser pulse. After compression, the ultrashort laser pulse is measured: energy above 16.0 J, S/N contrast ratio ~ 10^(5) : 1, filling factor ~>52.7%. Another long pulse beam is a non-compressed chirped laser pulse, which is measured: energy ~ 20 J, pulse duration 500 ps. The two beams are directed onto the target surface at an angle of 15°.
140.3280 laser amplifiers 190.4970 parametric oscillators and amplifiers Chinese Optics Letters
2003, 1(11): 14
1 中国科学院上海光学精密机械研究所
2 联邦德国马克斯-普朗克生物物理化学研究所
用吸收光谱对染料的Langmuir-Blodgett(LB)膜的聚集体在不同条件下进行了研究.典型的染料1-methyl-1’-octadecy1-2,2’-cyaninperchlorate(MOC)LB膜聚集体的吸收峰(J带)在580nm附近,吸收为0.09.刚制备好的样品随时间而改变其吸收特性,表明聚集体的结构在2hr后才趋于稳定;测定了不同样品J带的参数;吸收峰值波长位置和峰的半宽度,以及这些参数随温度的变化.吸收随温度变化的可逆性是LB膜聚集体用作光记录介质的一个物理基础.温度超过100℃时,样品吸收的不可逆变化反映相变发生.
MOC染料 单分子层或LB膜 吸收光谱
本文采用简单的几何光学方法分析了多模光纤对被传输激光的参量——脉宽与方向性的影响,实验与分析结果一致。
