Hentschel M, Kienberger R, Spielmann C, Reider G A, Milosevic N, Brabec T, Corkum P, Heinzmann U, Drescher M, Krausz F
Institut für Photonik, Technische Universität Wien, Gusshausstr. 27, A-1040 Wien, Austria.
Nature. 2001 Nov 29;414(6863):509-13. doi: 10.1038/35107000.
The generation of ultrashort pulses is a key to exploring the dynamic behaviour of matter on ever-shorter timescales. Recent developments have pushed the duration of laser pulses close to its natural limit-the wave cycle, which lasts somewhat longer than one femtosecond (1 fs = 10-15 s) in the visible spectral range. Time-resolved measurements with these pulses are able to trace dynamics of molecular structure, but fail to capture electronic processes occurring on an attosecond (1 as = 10-18 s) timescale. Here we trace electronic dynamics with a time resolution of </= 150 as by using a subfemtosecond soft-X-ray pulse and a few-cycle visible light pulse. Our measurement indicates an attosecond response of the atomic system, a soft-X-ray pulse duration of 650 +/- 150 as and an attosecond synchronism of the soft-X-ray pulse with the light field. The demonstrated experimental tools and techniques open the door to attosecond spectroscopy of bound electrons.
产生超短脉冲是在越来越短的时间尺度上探索物质动态行为的关键。最近的进展已将激光脉冲的持续时间推近其天然极限——波周期，在可见光谱范围内，该周期略长于1飞秒（1 fs = 10⁻¹⁵ s）。用这些脉冲进行的时间分辨测量能够追踪分子结构的动态变化，但无法捕捉在阿秒（1 as = 10⁻¹⁸ s）时间尺度上发生的电子过程。在这里，我们通过使用亚飞秒软X射线脉冲和几周期可见光脉冲，以≤150 as的时间分辨率追踪电子动力学。我们的测量表明原子系统的阿秒响应、650±150 as的软X射线脉冲持续时间以及软X射线脉冲与光场的阿秒同步。所展示的实验工具和技术为束缚电子的阿秒光谱学打开了大门。
