Ultra-short extreme ultraviolet pulses from the free-electron laser FLASH are characterized using terahertz-field driven streaking. Measurements at different ultra-short extreme ultraviolet wavelengths and pulse durations as well as numerical simulations were performed to explore the application range and accuracy of the method. For the simulation of streaking, a standard classical approach is used which is compared to quantum mechanical theory, based on strong field approximation. Various factors limiting the temporal resolution of the presented terahertz streaking setup are investigated and discussed. Special attention is paid to the cases of very short (∼10 fs) and long (up to ∼350 fs) pulses.

中文翻译：

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XUV脉冲在FLASH时的单次瞬态表征，持续时间约为10 fs至350 fs

使用太赫兹场驱动的条纹来表征来自自由电子激光器FLASH的超短极紫外脉冲。进行了在不同的超短极紫外波长和脉冲持续时间下的测量以及数值模拟，以探索该方法的应用范围和准确性。对于条纹的模拟，使用了标准的经典方法，该方法与基于强场近似的量子力学理论进行了比较。各种因素限制了提出的太赫兹条纹设置的时间分辨率。特别注意短脉冲（〜10 fs）和长脉冲（最高〜350 fs）的情况。