title: Attosecond beamline with actively stabilized and spatially separated beam paths.
abstract: We describe a versatile and compact beamline for attosecond spectroscopy. The setup consists of a high-order harmonic source followed by a delay line that spatially separates and then recombines the extreme-ultraviolet (XUV) and residual infrared (IR) pulses. The beamline introduces a controlled and actively stabilized delay between the XUV and IR pulses on the attosecond time scale. A new active-stabilization scheme combining a helium-neon-laser and a white-light interferometer minimizes fluctuations and allows to control delays accurately (26 as rms during 1.5 h) over long time scales. The high-order-harmonic-generation region is imaged via optical systems, independently for XUV and IR, into an interaction volume to perform pump-probe experiments. As a consequence of the spatial separation, the pulses can be independently manipulated in intensity, polarization, and frequency content. The beamline can be combined with a variety of detectors for measuring attosecond dynamics in gases, liquids, and solids.
authors.affiliation: Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Huppert
authors.affiliation: Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland.
authors.forename: I
authors.initials: I
authors.lastname: Jordan
authors.affiliation: Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland.
authors.forename: H J
authors.initials: HJ
authors.lastname: Wörner