Observation and Analysis of the 6 1<m:msubsup> Σ g + and 3 1Πg states of Rubidium Dimer

Detailed knowledge of the excited electronic states of Rubidium dimer is of significant importance to a number of areas of research such as, the production of ultracold ground state molecules, cold atom-molecule collisions, and the development of new ab-initio molecular electronic structure methods. The potential energy curves and transition dipole moments of dozens of electronic states of Rb₂ have been calculated. However, only few low-lying electronic states have been experimentally studied and assigned. We report our experimental work and analysis of the 6¹Σ_g⁺ and 3¹Π_g electronic states. In the experiment large number of ro-vibrational levels of the two states were observed using narrow band cw TiSa and dye laser in double resonance cascade configuration. The intermediate states used in the experiment are from the mutually perturbed A¹Σ_g⁺ ~ b³Π_u pair of states. Potential energy curve was generated for each state from the term values of the observed levels.