  Nonlinear spectroscopy in the extreme ultraviolet (EUV) and soft x-ray
spectral range offers the opportunity for element selective probing of
ultrafast dynamics using core-valence transitions (Mukamel et al., Acc. Chem.
Res. 42, 553 (2009)). We demonstrate a step on this path showing core-valence
sensitivity in transient grating spectroscopy with EUV probing. We study the
optically induced insulator-to-metal transition (IMT) of a VO2 film with EUV
diffraction from the optically excited sample. The VO2 exhibits a change in the
3p-3d resonance of V accompanied by an acoustic response. Due to the broadband
probing we are able to separate the two features.
