Probing Rydberg-Rydberg interactions in N by ultrafast EUV-NIR photoelectron spectroscopy.

The ultrafast dynamics of molecular nitrogen (N) just below the ionization threshold has been investigated by time-resolved photoelectron spectroscopy using a single harmonic centered at hν = 15.38 eV. The evolution of the Rydberg wavepacket launched by the ultrashort EUV pulse is probed by a time-delayed femtosecond NIR laser pulse.