Spectroscopy of Cs_2, RbCs, and Rb_2 in solid ~4He

摘要

We present comparative experimental and theoretical studies of the absorption and fluorescence spectra of the alkali-metal dimer molecules Cs _2 and RbCs immersed in a solid helium matrix, thereby extending our recent observations of Rb_2 in solid ~4He. The laser-excited molecular states are mostly quenched by the interaction with the He matrix. The quenching efficiently populates the second lowest excited state of the molecule, i.e., (1) ~2Π_((u)) that is metastable in the homonuclear dimers. Molecular excitation and emission bands are modeled by calculating Franck-Condon factors that give a reasonable agreement with the experimental findings.