Interference effects in two-photon ATI by multiple orders high harmonics   with random or locked phases
  We numerically study 2-photon processes using a set of harmonics from a Ti:Sapphire laser and in particular interference effects in the Above Threshold Ionization spectra. We compare the situation where the harmonic phases are assumed locked to the case where they have a random distribution. Suggestions for possible experiments, using realistic parameters are discussed. 
Eric Cormier, Anna Sanpera, Maciej Lewenstein and Pierre Agostini