Fluorescence excitation and resonantly enhanced photoionization spectra of the C-X and D-X bands of XeNe, XeAr, and XeKr, formed in a supersonic free jet are measured by use of a tunable vacuum ultraviolet light generated by four-wave difference frequency mixing of two lasers in Kr. The potential parameters of the heteronuclear rare gas dimers for the two excited state potentials, C1 and D0+, correlated with the Xe6s′ (1/2)1 state are derived by an analysis of rovibronic structures of the C-X and D-X bands. The dissociation energies De for the C and D states are, respectively, determined to be 244 and 112 cm-1 for XeAr and are 1445 and 54 cm-1 for XeKr. © 1990 American Institute of Physics.