  We present an innovative beamline for extreme ultraviolet (XUV)-infrared (IR)
pump-probe reflection spectroscopy in solids with attosecond temporal
resolution. The setup uses an actively stabilized interferometer, where
attosecond pulse trains or isolated attosecond pulses are produced by
high-order harmonic generation in gases. After collinear recombination, the
attosecond XUV pulses and the femtosecond IR pulses are focused twice in
sequence by toroidal mirrors, giving two spatially separated interaction
regions. In the first region, the combination of a gas target with a
time-of-flight spectrometer allows for attosecond photoelectron spectroscopy
experiments. In the second focal region, an XUV reflectometer is used for
attosecond transient reflection spectroscopy (ATRS) experiments. Since the two
measurements can be performed simultaneously, precise pump-probe delay
calibration can be achieved, thus opening the possibility for a new class of
attosecond experiments on solids. Successful operation of the beamline is
demonstrated by the generation and characterization of isolated attosecond
pulses, the measurement of the absolute reflectivity of SiO2, and by performing
simultaneous photoemission/ATRS in Ge.
