Measurement of the Na2 51Σ+g→ A1Σ+ u and 61Σ+g→ A1Σ+ u u transition dipole moments using optical-optical double resonance and Autler--Townes spectroscopy.

Accurate knowledge of transition dipole moment matrix elements is crucial since important parameters associated with the interaction of light with matter, such as emission and absorption line intensities, lifetimes and Einstein coefficients, depend on these matrix elements.We report here an experimental study of the Na2 51Σ+g ↔ A1Σ+ u and 61Σ+g↔ A1Σ+ u electronic transition dipole moments and their dependence on internuclear distance. We have measured absolute transition dipole matrix elements for ro-vibrational transitions of the Na2 51Σ+g↔ A1Σ+ u and 61Σ+g↔ A1Σ+ u electronic transitions using Autler-Townes and optical-optical double resonance spectroscopy, and we compare the results to ab initio theoretical values [A. Sanli et al., J. Chem. Phys. 143, 104304 (2015)]. [ABSTRACT FROM AUTHOR]