强激光与粒子束
2023, 35(5): 052001
1 中国计量大学光学与电子科技学院,浙江 杭州 310018
2 中国工程物理研究院上海激光等离子体研究所,上海 201800
定量分析光纤阵列位移及指向扰动偏差对合束激光光束质量因子M2的影响规律是实现合束激光光束质量有效控制的前提。根据衍射积分推导了紧凑型光谱组束系统中光纤阵列存在不同位移、指向扰动时合束激光的远场光强分布,利用Heisenberg不确定性原理推导出了合束激光光束质量因子M2的表达式。在恒定的子束数目下,分析了单路/多路光束分别存在位移、指向扰动偏差时合束激光光束质量因子M2的变化情况,并在一定的随机位移、指向扰动偏差下对不同子束数量的合束激光的光束质量因子M2进行了误差分析。结果显示:合束激光光束质量因子M2对沿光纤端面水平(x轴)方向的扰动量最为敏感,需要控制在微米量级;确定了光纤阵列的不同扰动量与合束激光光束质量因子M2之间的定量关系,给出了光纤阵列位移、指向精度控制要求;当参与合束的子束数量超过23束时,在特定的随机扰动量下,合束激光的光束质量因子M2的统计均值分别趋向各自的稳定值1.37、1.34、1.25,而标准差分别趋于0.05、0.06、0.04。
光纤光学 光纤阵列 光束质量 光谱组束 紧凑型组束系统
强激光与粒子束
2021, 33(7): 071005
红外与激光工程
2020, 49(12): 20201074
强激光与粒子束
2020, 32(11): 112009
Author Affiliations
Abstract
1 Shanghai Institute of Laser Plasma, China Academy of Engineering Physics, Shanghai 201899, China
2 State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
3 School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
The use of low-coherence light is expected to be one of the effective ways to suppress or even eliminate the laser–plasma instabilities that arise in attempts to achieve inertial confinement fusion. In this paper, a review of low-coherence high-power laser drivers and related key techniques is first presented. Work at typical low-coherence laser facilities, including Gekko XII, PHEBUS, Pharos III, and Kanal-2 is described. The many key techniques that are used in the research and development of low-coherence laser drivers are described and analyzed, including low-coherence source generation, amplification, harmonic conversion, and beam smoothing of low-coherence light. Then, recent progress achieved by our group in research on a broadband low-coherence laser driver is presented. During the development of our low-coherence high-power laser facility, we have proposed and implemented many key techniques for working with low-coherence light, including source generation, efficient amplification and propagation, harmonic conversion, beam smoothing, and precise beam control. Based on a series of technological breakthroughs, a kilojoule low-coherence laser driver named Kunwu with a coherence time of only 300 fs has been built, and the first round of physical experiments has been completed. This high-power laser facility provides not only a demonstration and verification platform for key techniques and system integration of a low-coherence laser driver, but also a new type of experimental platform for research into, for example, high-energy-density physics and, in particular, laser–plasma interactions.
Matter and Radiation at Extremes
2020, 5(6): 065201
强激光与粒子束
2020, 32(1): 011004
1 中国工程物理研究院上海激光等离子体研究所, 上海 201800
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
在理论和实验上,分析了皮秒激光脉冲抽运所产生的参量荧光的时间相干特性。通过引入二阶复相干度,理论研究了在信号光与闲频光群速度走离存在的条件下,抽运功率和抽运脉宽对参量荧光时间相干性的影响。计算结果表明适当的抽运功率和较短的抽运脉宽是提升参量荧光时间相干性的重要条件,而过高的抽运功率或者较宽的抽运脉宽则会降低参量荧光的时间相干性。利用周期极化铌酸锂晶体,在实验上对理论结果进行了初步的实验验证。
非线性光学 参量荧光 相干性 光参量产生
Author Affiliations
Abstract
1 Shanghai Institute of Laser Plasma, 1129 Chenjiashan Road, Jiading, Shanghai 201800, China
2 IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China
3 Shanghai Institute of Optics and Fine Mechanics, 390 Qinghe Road, Jiading, Shanghai 201800, China
4 Laser Fusion Research Center, P.O. Box 919-981, Mianyang, Sichuan 621900, China
Based on the premise that further improvements to the size and damage threshold of large-aperture optical components are severely limited, coherent beam combining (CBC) is a promising way to scale up the available peak power of pulses for ultrashort ultrahigh intensity laser systems. Spectral phase effects are important issues and have a significant impact on the performance of CBC. In this work, we analyze systematically factors such as spectral dispersions and longitudinal chromatism, and get the general spectral phase control requirements of CBC for ultrashort ultrahigh intensity laser systems. It is demonstrated that different orders of dispersion influence intensity shape of the combined beam, and high-order dispersions affect the temporal contrast of the combined beam, while the number of the channels to be combined has little impact on the temporal Strehl ratio (SR) of the combined beam. In addition, longitudinal chromatism should be controlled effectively since it has a detrimental effect on the combined beam at the focal plane, both temporally and spatially.
Laser beam combining Ultrafast lasers Systems design Collection Of theses on high power laser and plasma physics
2016, 14(1): 10124