The Na 2 2 3Δ g state: CW perturbation-facilitated optical-optical double resonance spectroscopy

Abstract

The Na 2 ( σ g 3 s)(4 dδ g ) 2 3Δ g state has been studied by CW sub-Doppler perturbation-facilitated optical-optical double resonance (PFOODR) spectroscopy. Twenty-three vibrational levels have been observed with resolved fine-hyperfine structure. The fine-hyperfine coupling scheme of the 2 3Δ g state is exactly the same as the Na 2 ( σ g 3 s)(3 dδ g ) 1 3Δ g : case b βs coupling with Fermi contact constant b = 221.7 MHz. Absolute vibrational numbering of the 2 3Δ g state has been determined from the PFOODR fluorescence to the b 3Π u state. The Dunham coefficients were then derived and the corresponding RKR potential curve was determined.