Femtosecond wave packet propagation in spin-orbit coupled electronic states of the Na2 molecule

The vibrational dynamics of the excited electronic A 1σu+ state of Nat for two pump wavelengths λpump = 620 and 642 nm are investigated. Preparing a wave packet on the A state shows fast dominant oscillations with periods of ∼- 312 ∼ 297 fs. For λ pump = 620 nm a first revival centered around 47 ps found and for λpump = 642 nm the first revival already appears after 14 ps (center). Fourier analysis of the 60 ps scans with a resolution of 0.05 cm−1 enables the detailed and identification of the excited vibrational levels of the A state. By comparison with RKR data, energy shifts of the level u = 8 due to spin-orbit coupling (SOC) with the b 3πu state is determined to be 0.85 cm−1.