Laboratory of Physical Chemistry, ETH Zürich, 8093, Zurich, Switzerland.
European XFEL GmbH, 22869, Schenefeld, Germany.
Sci Rep. 2023 Feb 21;13(1):3059. doi: 10.1038/s41598-023-29089-8.
We present an apparatus for attosecond transient-absorption spectroscopy (ATAS) featuring soft-X-ray (SXR) supercontinua that extend beyond 450 eV. This instrument combines an attosecond table-top high-harmonic light source with mid-infrared (mid-IR) pulses, both driven by 1.7-1.9 mJ, sub-11 fs pulses centered at 1.76 [Formula: see text]m. A remarkably low timing jitter of [Formula: see text] 20 as is achieved through active stabilization of the pump and probe arms of the instrument. A temporal resolution of better than 400 as is demonstrated through ATAS measurements at the argon L[Formula: see text]-edges. A spectral resolving power of 1490 is demonstrated through simultaneous absorption measurements at the sulfur L[Formula: see text]- and carbon K-edges of OCS. Coupled with its high SXR photon flux, this instrument paves the way to attosecond time-resolved spectroscopy of organic molecules in the gas phase or in aqueous solutions, as well as thin films of advanced materials. Such measurements will advance the studies of complex systems to the electronic time scale.
我们提出了一种用于阿秒瞬态吸收光谱（ATAS）的设备，其特点是具有软 X 射线（SXR）超连续谱，其延伸超过 450 eV。该仪器结合了阿秒台式高次谐波光源和中红外（mid-IR）脉冲，两者均由中心波长为 1.76 [Formula: see text] m 的 1.7-1.9 mJ、11 fs 以下的脉冲驱动。通过对仪器的泵浦臂和探测臂进行主动稳定，实现了低至[Formula: see text] 20 的出色定时抖动。通过在氩 L[Formula: see text] 边缘进行 ATAS 测量，证明了优于 400 的时间分辨率。通过在 OCS 的硫 L[Formula: see text] 和碳 K 边缘同时进行吸收测量，证明了 1490 的光谱分辨能力。结合其高 SXR 光子通量，该仪器为气相或水溶液中以及先进材料的薄膜中的有机分子的阿秒时间分辨光谱学铺平了道路。这些测量将把复杂体系的研究推进到电子时间尺度。
