Max-Planck-Institut für Quantenoptik, Hans-Kopfermann Straße 1, 85748, Garching, Germany.
Ludwig-Maximilian-Universität München, Am Coulombwall 1, 85748, Garching, Germany.
Nat Commun. 2018 Nov 26;9(1):4992. doi: 10.1038/s41467-018-07421-5.
The interaction of ultra-intense laser pulses with matter opened the way to generate the shortest light pulses available nowadays in the attosecond regime. Ionized solid surfaces, also called plasma mirrors, are promising tools to enhance the potential of attosecond sources in terms of photon energy, photon number and duration especially at relativistic laser intensities. Although the production of isolated attosecond pulses and the understanding of the underlying interactions represent a fundamental step towards the realization of such sources, these are challenging and have not yet been demonstrated. Here, we present laser-waveform-dependent high-order harmonic radiation in the extreme ultraviolet spectral range supporting well-isolated attosecond pulses, and utilize spectral interferometry to understand its relativistic generation mechanism. This unique interpretation of the measured spectra provides access to unrevealed temporal and spatial properties such as spectral phase difference between attosecond pulses and field-driven plasma surface motion during the process.
超强度激光脉冲与物质的相互作用为产生目前在阿秒领域可用的最短光脉冲开辟了道路。被称为等离子体镜的电离固体表面是增强阿秒源在光子能量、光子数和持续时间方面的潜力的有前途的工具，特别是在相对论激光强度下。尽管孤立的阿秒脉冲的产生和对基础相互作用的理解是实现这种源的基本步骤，但这些步骤具有挑战性，尚未得到证明。在这里，我们展示了在极紫外光谱范围内依赖于激光波形的高阶谐波辐射，支持良好孤立的阿秒脉冲，并利用光谱干涉测量来理解其相对论产生机制。这种对测量光谱的独特解释提供了对未揭示的时间和空间特性的访问，例如阿秒脉冲之间的光谱相位差和过程中场驱动等离子体表面运动。
