LASER-INDUCED FLUORESCENCE, ENERGY-TRANSFER, AND DISSOCIATION OF CS2

Laser induced fluorescences of Cs2 excited by the Ar+ laser lines have been studied. A series of lines with vibrational progression and the successive diffuse bands in the region down to 16200 cm-1 were found to be polarized and identified as the resonance fluorescence. The diffuse fluctuation band with a maximum of intensity at 16400 cm-1 consists of several bands at regular interval and it was independent on the line of excitation. By applying the theory on the role of kinetic energy in the Franck-Condon principle proposed by Mulliken, the band was identified as a transition from the internuclear distance of maximum kinetic energy in the vibrational level of the excited state E 1Πu. All the other fluorescence bands of low frequency were observed to be depolarized completely, and the intensities increased when a foreign gas was added. These bands were identified as the fluorescence from the states which were populated by collision-induced transitions from the E state. Atomic fluorescence 6p 2P3/2→6s 2S1/2 is interpreted as the production of the excited atom Cs 6p 2P3/2 by predissociation of Cs2 E 1Πu through interaction with, most probably, Cs2 B 1Πu. © 1979 American Institute of Physics.