Tunable VUV laser based spectrometer for Angle Resolved Photoemission   Spectroscopy (ARPES)
  We have developed an angle-resolved photoemission spectrometer with tunable VUV laser as a photon source. The photon source is based on the fourth harmonic generation of a near IR beam from a Ti:sapphire laser pumped by a CW green laser and tunable between 5.3eV and 7eV. The most important part of the set-up is a compact, vacuum enclosed fourth harmonic generator based on KBBF crystals, grown hydrothermally in the US. This source can deliver a photon flux of over 10^14 photons/s. We demonstrate that this energy range is sufficient to measure the kz dispersion in an iron arsenic high temperature superconductor, which was previously only possible at synchrotron facilities. 
Rui Jiang, Daixiang Mou, Yun Wu, Lunan Huang, Colin D. McMillen,   Joseph Kolis, Henry G. Giesber III, John J. Egan, Adam Ka...
physics.optics cond-mat.str-el