High Resolution Spectroscopy Study of the Rubidium Dimer

Abstract

This dissertation reports high-resolution experimental study and numerical analysis of the rubidium dimer 31Πg, "6" ^"1" "Σ" _"g" ^"+" , "3" ^"3" "Π" _"g" , and "4" ^"3" "Σ" _"g" ^"+" excited electronic states. The term energies of over 2 400 observed ro-vibrational levels spanning a large range of rotational and vibrational quantum numbers were measured with the perturbation facilitated optical-optical double resonance technique 24 000 cm-1 – 26 000 cm-1 above the ground state minimum of Rb2. The excited electronic states were probed by exciting Rb2 molecules from the thermally populated ro-vibrational levels of the "X" ^" 1" "Σ" _"g" ^"+" ground electronic state through intermediate levels of the mixed" " "A" ^"1" "Σ" _"u" ^"+" " ~ " "b" ^"3" "Π" _"u" electronic states. Probe laser resonance was detected by measuring the laser induced fluorescence from the excited electronic states to the "a" ^"3" "Σ" _"u" ^"+" triplet ground state. The ro-vibrational term energies from each electronic state were fit to molecular constants using the Dunham expansion. These molecular constants were subsequently used to generate Rydberg-Klein-Rees model potential energy functions. The spin multiplicity of the electronic states as well as the vibrational numbering of the triplet electronic states were determined by resolving the bound-free emission from the excited ro-vibrational levels to the triplet ground state.