X-ray pulses approaching the attosecond frontier
X-ray pulses approaching the attosecond frontier
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DOI：
10.1126/science.1058561
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发表时间：
2001-03-09
期刊：
影响因子：
56.9
通讯作者：
Krausz, F
中科院分区：
文献类型：
--
作者：
Drescher, M;Hentschel, M;Krausz, F
单软X射线脉冲类似于90电子伏（eV）的光子能量产生的高次谐波产生与7飞秒（fs），770纳米（1.6 eV）的激光脉冲，其特征在于光致电离氪在驱动激光脉冲的存在。通过检测垂直于激光偏振方向射出的光电子，抑制了由于激光光子的吸收和发射而导致的光电子谱的展宽，从而允许在互相关测量中以亚激光周期分辨率观察激光诱导的能谱下移。我们测量了持续时间为1.8（+0.7/-1.2）fs的孤立X射线脉冲，其短于驱动激光的振荡周期（2.6 fs）。我们的生成和测量技术在广泛的X射线波长范围内提供亚飞秒分辨率，为实验阿秒科学铺平了道路。追踪原子的演化过程比激发光场的演化速度更快是触手可及的。
Single soft-x-ray pulses of similar to 90-electron volt (eV) photon energy are produced by high-order harmonic generation with 7-femtosecond (fs), 770-nanometer (1.6 eV) Laser pulses and are characterized by photoionizing krypton in the presence of the driver laser pulse. By detecting photoelectrons ejected perpendicularly to the Laser polarization, broadening of the photoelectron spectrum due to absorption and emission of Laser photons is suppressed, permitting the observation of a Laser-induced downshift of the energy spectrum with sub-laser-cycle resolution in a cross correlation measurement. We measure isolated x-ray pulses of 1.8 (+0.7/-1.2) fs in duration, which are shorter than the oscillation cycle of the driving Laser Light (2.6 fs). Our techniques for generation and measurement offer sub-femtosecond resolution over a wide range of x-ray wavelengths, paving the way to experimental attosecond science. Tracing atomic processes evolving faster than the exciting light field is within reach.