Spectroscopy and dynamics of superexcited molecules as probed by fluorescence measurements

Neutral dissociation (ND) of superexcited molecules is one of the foremost interests in the photophysics of in the extreme-ultraviolet region. The recent progress in the studies of ND which has been achieved by measuring the yield spectra of fluorescence radiation emitted from excited fragments is presented in this paper. A sensitive spectroscopy of highly-lying superexcited states, in particular, molecular doubly excited states having both bound and repulsive potential curves (surfaces) is demonstrated. Also shown is the two dimensional (2D) spectroscopy of vuv-fluorescence radiation for revealing the ND decay dynamics and potential structure of superexcited states simultaneously.