Experimental setup for visible pump/XUV probe ARPES: the visible beam (1.55 or 3.1 eV) traverses a delay stage that controls the timing of the pulses; the XUV beam is produced via HHG in argon, propagates through a TDCM for spectral selection, and is refocused almost collinearly with the visible beam on the sample in a UHV chamber, containing a hemispherical electron analyzer.
(a) An image of the beam on the CCD camera containing all harmonics. The average size is FWHM. (b) Interference pattern of H13 from a double-pinhole ( in diameter, apart). The outer ring results from overlapping diffraction Airy patterns originating from both pinholes.
Photoemission spectrum from using a XUV beam containing all generated high-harmonics. The peaks are replicas of the electronic structure near the Fermi edge, separated by . Analyzer work function is .
Photoemission spectra of copper, obtained by selecting individual harmonics. The peaks originate from electrons; the small step above the peak represents the Fermi edge.
Angle-integrated photoemission of using . The inset shows the spectrum obtained at SRC (Stoughton, WI) using .
(a) Angle-integrated photoemission from GaAs at 12 K using . (b) Angle-resolved photoemission at ±4° analyzer acceptance angle; the range of accessible momentum values is split in 25 channels. (c) The resulting energy-momentum photoemission map.
Angle-resolved photoemission map of at 12 K using .
(a) Photoelectron spectra of Ge at time delay of 0 (dotted line) and 30 ps (solid line) between the pump and probe pulses. Pump pulse intensity was . Inset: static photoemission of Ge using . (b) Dynamics of the transient electron population, integrated in the 19–22 eV kinetic energy range.
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