Makos I, Orfanos I, Nayak A, Peschel J, Major B, Liontos I, Skantzakis E, Papadakis N, Kalpouzos C, Dumergue M, Kühn S, Varju K, Johnsson P, L'Huillier A, Tzallas P, Charalambidis D
Foundation for Research and Technology - Hellas, Institute of Electronic Structure & Laser, GR71110, Heraklion, Crete, Greece.
Department of Physics, University of Crete, GR71003, Heraklion, Crete, Greece.
Sci Rep. 2020 Feb 28;10(1):3759. doi: 10.1038/s41598-020-60331-9.
The quantum mechanical motion of electrons and nuclei in systems spatially confined to the molecular dimensions occurs on the sub-femtosecond to the femtosecond timescales respectively. Consequently, the study of ultrafast electronic and, in specific cases, nuclear dynamics requires the availability of light pulses with attosecond (asec) duration and of sufficient intensity to induce two-photon processes, essential for probing the intrinsic system dynamics. The majority of atoms, molecules and solids absorb in the extreme-ultraviolet (XUV) spectral region, in which the synthesis of the required attosecond pulses is feasible. Therefore, the XUV spectral region optimally serves the study of such ultrafast phenomena. Here, we present a detailed review of the first 10-GW class XUV attosecond source based on laser driven high harmonic generation in rare gases. The pulse energy of this source largely exceeds other laser driven attosecond sources and is comparable to the pulse energy of femtosecond Free-Electron-Laser (FEL) XUV sources. The measured pulse duration in the attosecond pulse train is 650 ± 80 asec. The uniqueness of the combined high intensity and short pulse duration of the source is evidenced in non-linear XUV-optics experiments. It further advances the implementation of XUV-pump-XUV-probe experiments and enables the investigation of strong field effects in the XUV spectral region.
在空间上局限于分子尺寸的系统中,电子和原子核的量子力学运动分别发生在亚飞秒到飞秒的时间尺度上。因此,对超快电子动力学以及特定情况下的核动力学的研究,需要有持续时间为阿秒(asec)且强度足以引发双光子过程的光脉冲,这对于探测系统的内在动力学至关重要。大多数原子、分子和固体在极紫外(XUV)光谱区域有吸收,在该区域合成所需的阿秒脉冲是可行的。因此,XUV光谱区域非常适合用于此类超快现象的研究。在此,我们对基于稀有气体中激光驱动高次谐波产生的首个10吉瓦级XUV阿秒光源进行详细综述。该光源的脉冲能量大大超过其他激光驱动的阿秒光源,并且与飞秒自由电子激光(FEL)XUV光源的脉冲能量相当。在阿秒脉冲序列中测得的脉冲持续时间为650±80阿秒。该光源高强度与短脉冲持续时间相结合的独特性在非线性XUV光学实验中得到了证明。它进一步推动了XUV泵浦-XUV探测实验的开展,并能够研究XUV光谱区域中的强场效应。