High-order harmonic generation in rare gases : a new source in photoionization spectroscopy

Summary, in English

We demonstrate that we can use the extreme ultraviolet radiation produced by high order harmonic generation to perform photoionization experiments. With harmonics from the 11th to the 69th of a 140 fs Cr:LiSAF laser operating at 825 nm, we measure the relative photoionization cross sections of xenon, krypton, argon and neon over the range 10 to 110 eV. With narrow bandwidth harmonics produced by a tunable, 1 ps dye laser, we observe the autoionizing states between the 4 p⁵ ionization thresholds in krypton.