Electron spectroscopy after photo-ionization constitutes a convenient tool to study the energy levels in solids, liquids and gases. In particular, angle-resolved photoemission spectroscopy (ARPES) has become invaluable for the determination of the electronic bandstructure in solids over a large range of the Brillouin zone [1]. In combination with a pump-probe scheme empowered by femtosecond lasers, time- and angle-resolved ARPES allows to investigate the momentum-resolved relaxation of photoexcited charge carriers [2,3]. Additional insights can be obtained from ARPES microscopy [4].

These applications benefit from the recent advances in fiber-based femtosecond laser technology: laser pulse energies in the mJ range provide sufficient energy to drive the experiment while kHz to MHz repetition rates enable data acquisition in a timely fashion. Moreover, inner-atomic electronic levels can be excited by XUV radiation (HHG) derived from table-top laser sources. AFS offers several laser system that can drive typical photo-emission spectroscopy experiments.