Author Affiliations
Abstract
1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2 Songshan Lake Materials Laboratory, Dongguan 523808, China
3 University of Chinese Academy of Sciences, Beijing 100049, China
4 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
Isolated attosecond pulses (IAPs) are generated via applying amplitude gating on high-order harmonic generation driven by carrier-envelope phase stabilized 5.2 fs pulses with 0.5 mJ pulse energy at 770 nm central wavelength at the Synergetic Extreme Condition User Facility. A continuum ranging from 70 to 100 eV that supports sub-100-attosecond pulse is extracted by Zr foil and Mo/Si multilayer mirror. We demonstrate the characterization of the IAP. The retrieved pulse duration is 86 attoseconds. The developed attosecond laser beamline with repetition rate up to 10 kHz is available for users to conduct attosecond photoelectron spectroscopy researches with a capability of coincidence measurement.
amplitude gating coincidence FROG-CRAB high-order harmonic generation isolated attosecond pulses Chinese Optics Letters
2023, 21(11): 113201
1 西安电子科技大学物理与光电工程学院, 陕西 西安 710071
2 中国科学院物理研究所, 北京凝聚态物理国家研究中心, 北京 100190
3 松山湖材料实验室, 广东 东莞 523808
4 中国科学院大学物理科学学院, 北京 100049
超快激光再生放大过程具有复杂的动力学行为, 需要建立模型进行求解和迭代计算。基于改进的 Frantz-Nodvik 方程计算了 Yb:KGW 晶体再生放大器的输出性质, 研究了泵浦强度、晶体长度和泵浦脉宽对放大器输出性能的影响, 同时对不同重复频率再生放大器的输出行为进行了分析。在此基础上设计了再生放大器, 得到了重复频率 1 kHz、单脉冲能量 1 mJ 的激光放大结果, 与理论分析结果符合得较好。该改进的 Frantz-Nodvik 方程对于设计高重复频率、大能量且性能稳定的激光放大器具有参考价值。
激光技术 Frantz-Nodvik 方程 掺镱放大器 再生放大 laser techniques Frantz-Nodvik equation ytterbium-doped amplifier regenerative amplifier
1 西安电子科技大学物理与光电工程学院, 陕西 西安 710126
2 中国科学院物理研究所, 北京凝聚态物理国家实验室, 北京 100190
3 松山湖材料实验室, 广东 东莞 523808
4 中国科学院大学物理学院, 北京 100049
在啁啾脉冲放大 (CPA) 系统中, 时域展宽器与压缩器的匹配是获得高对比度飞秒脉冲的关键。相比较常规的 Martinez 和 ffner 结构的展宽器, 基于同心结构的展宽器由于物与像完全重合, 可以消除像差带来的高阶色散的影响, 进而采用光栅对压缩器以获得更好的压缩效果。透射光栅对和凹面反射镜组合实现的同心展宽器具有结构紧凑的优点, 将该展宽器替代原有的 Martinez 型展宽器, 在重复频率为 1 kHz、泵浦功率为 11.4 W 的泵浦条件下, 展宽后的啁啾脉冲经环形腔钛宝石再生放大器进行能量放大, 再由光栅对进行压缩, 可获得脉冲宽度为 47.5 fs 的压缩结果, 接近于光谱带宽 22.1 nm 的傅里叶变换极限。该结果表明基于透射光栅的同心展宽器可以获得较好的飞秒脉冲压缩效果。
激光技术 飞秒激光 啁啾脉冲放大 脉冲展宽器 再生放大器 laser techniques femtosecond laser chirped-pulse amplification pulse stretcher regenerative amplifier
强激光与粒子束
2021, 33(11): 111008
Author Affiliations
Abstract
1 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
2 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3 School of Physical Science, University of Chinese Academy of Sciences, Beijing 100049, China
4 School of Physics and Astronomy, Sun Yat-sen University, Zhuhai 519082, China
5 Songshan Lake Materials Laboratory, Dongguan 523808, China
We report a high power fiber amplifier based on nonlinear chirped-pulse amplification (NCPA). To manage the nonlinearity, pulse shaping is introduced by self-phase modulation in the fiber stretcher with the help of spectral filtering. The third-order dispersion is compensated for by the nonlinear phase shift in the NCPA. With optimization, the system can output 382 fs pulse duration with 20 W average power at 1 MHz repetition rate. The long-term average power fluctuation is measured to be 0.5% in 24 h, and the beam quality factor () is 1.25.
nonlinear chirped-pulse amplification spectral shaping fiber amplifier Chinese Optics Letters
2021, 19(9): 091401
Author Affiliations
Abstract
1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
4 Songshan Lake Materials Laboratory, Dongguan 523808, China
5 CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China
We demonstrate nonlinear pulse compression of an 8 kHz Nd: picosecond laser using the multi-pass-cell (MPC) technique with fused silica as the nonlinear medium. The pulse duration is compressed from 12.5 ps to 601 fs, corresponding to a pulse shortening factor of 20.8. The output pulse energy is 154 μJ with an efficiency of 74.5%. To the best of our knowledge, this is the highest pulse compression ratio achieved in a single-stage MPC with bulk material as the nonlinear medium. The laser power stability and the beam quality () before and after the MPC are also experimentally studied. Both the laser power stability and the beam quality are barely deteriorated by the MPC device.
multi-pass cell Nd:YVO4 compression ratio femtosecond laser Chinese Optics Letters
2021, 19(9): 093201
1 西安电子科技大学物理与光电工程学院, 陕西 西安 710071
2 中国科学院物理研究所, 北京凝聚态物理国家研究中心, 北京 100190
3 中国科学院大学, 北京 100049
4 松山湖材料实验室, 广东 东莞 523808
基于极紫外波段高次谐波产生(high-order harmonic generation, HHG)的光学选通技术已成为目前人们获得孤立阿秒脉冲(isolated attosecond pulse, IAP)的重要手段。由于IAP继承了驱动激光脉冲的光学属性和重复频率,因此具有良好的时空相干性和方向性。近转换极限极短脉宽IAP的产生不仅需要在极紫外区域有较宽的连续光谱支持,还需要对其所携带的本征色散进行补偿。据此,本文从理论上模拟计算了多组阿秒脉冲光谱、本征色散和金属膜材料色散的参数组合,在中心光谱98,120,170 eV附近的结果表明,选用不同厚度的锆膜、钼膜和锡膜对应中心能量的高次谐波可以实现色散补偿。最终确定120 eV中心光子能量加钼膜的组合有可能在较高的产生效率下产生近40 as的IAP。基于上述参数选择,设计了一套由非共线阿秒条纹相机和平场光谱仪组成的极紫外阿秒束线及相应的真空系统,该系统可用于高次谐波及阿秒脉冲的测量。
激光光学 高次谐波 孤立阿秒脉冲 阿秒脉冲本征色散 阿秒条纹相机
1 中国科学院物理研究所北京凝聚态物理国家研究中心, 北京 100190
2 松山湖材料实验室, 广东 东莞 523808
3 中国科学院大学, 北京 100049
4 北京交通大学理学院微纳材料及应用研究所, 北京 100044
5 西安电子科技大学物理与光电工程学院, 陕西 西安 710071
自从2001年人们首次实现单个独立的阿秒(1 as=10 -18 s)脉冲以来,阿秒脉冲作为超快光学最前沿的内容,在近20年的时间内得到了长足的发展,为人们在电子运动的自然时间尺度中观测量子世界的基本动力学过程提供了崭新的研究手段,并开启了阿秒科学这一全新的研究领域,覆盖了原子、分子、凝聚态物理、化学、生物等诸多学科的不同研究需求。随着飞秒激光驱动器技术的不断发展,目前阿秒脉冲不仅脉冲宽度突破了50 as,而且也进一步朝着更高单脉冲能量(高通量)、更短波长(高光子能量)、更高重复频率的方向发展。本文将结合高次谐波相位匹配及高能量飞秒超强激光、双色及多色相干合成飞秒激光、中红外飞秒激光、高重复频率飞秒激光等驱动技术,综述介绍阿秒脉冲在上述各方面的新进展,并展望了未来进一步的发展趋势。
激光光学 超快激光 阿秒脉冲 高次谐波 相位匹配
1 中国科学院物理研究所, 北京 100190
2 中国气象局乌鲁木齐沙漠气象研究所, 新疆 乌鲁木齐 830002
对太瓦 (TW) 飞秒激光在自然大气中传输时产生的超长等离子体通道的物理性质进行了研究。试验结果证实 2 TW 飞秒激光在大气中自由传输时实 现了 2 km 长的等离子体通道, 长距离传输后通道内的等离子体电子密度约为 1011 cm-3, 仍然保持良好的导电性。高压放电试验也证实了有等离子体通道存在, 可以将放电电压降低 30%, 说明激光诱导高压放电的有效性。本次试验研究表明长度为公里量级、长寿命大气等离子体通道的实现是可行的, 将为激光引雷、大气监测、人工干预气候等实用化应用扫清技术上的障碍。
激光技术 超短脉冲激光 等离子体通道 大气成丝 激光引雷 飞秒激光 laser technology ultrashort pulse laser plasma channel filamentation laser induced lightning femtosecond laser
Author Affiliations
Abstract
1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Songshan Lake Materials Laboratory, Dongguan 523808, China
4 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
We demonstrate a harmonically pumped femtosecond optical parametric oscillator (OPO) laser using a frequency-doubled mode-locked Yb:KGW laser at a repetition rate of 75.5 MHz as the pump laser. Based on a bismuth borate nonlinear crystal, repetition rates up to 1.13 GHz are realized, which is 15 times that of the pump laser. The signal wavelength is tunable from 700 nm to 887 nm. The maximum power of the signal is 207 mW at the central wavelength of 750 nm and the shortest pulse duration is 117 fs at 780 nm. The beam quality (M2 factor) in the horizontal and vertical directions of the output beam are 1.077 and 1.141, respectively.
GHz femtosecond laser optical parametric oscillator tunable wavelength Chinese Optics Letters
2020, 18(3): 033201
