Extending optical fs metrology to XUV attosecond pulses

We report on the progress towards a 2nd-order autocorrelation measurement of a coherent superposition of the 7th to the 15th harmonic of the fundamental frequency of the Ti : Sapphire laser. The two-photon ionization of He atoms was investigated and found to be an appropriate non-linear detector. In addition, the technique of volume autocorrelation based on a split mirror wavefront divider was analysed and shown to exhibit adequate degree of modulation. Moreover, the approach presented opens up the path to XUV-pump XUV-probe type of temporal studies of ultrafast processes with a sub-fs temporal resolution.