Femtosecond Spectroscopy with Vacuum Ultraviolet Pulse Pairs
  We combine different wavelengths from an intense high-order harmonics source with variable delay at the focus of a split-mirror interferometer to conduct pump-probe experiments on gas-phase molecules. We report measurements of the time resolution (<44 fs) and spatial profiles (4 {\mu}m x 12 {\mu}m) at the focus of the apparatus. We demonstrate the utility of this two-color, high-order-harmonic technique by time resolving molecular hydrogen elimination from C2H4 excited into its absorption band at 161 nm. 
T. K. Allison, T. W. Wright, A. M. Stooke, C. Khurmi, J. van Tilborg,   Y. Liu, R. W. Falcone, and A. Belkacem
physics.chem-ph physics.atom-ph