Spectra of the B 3Σ-- X 3Σ- transition in SO above the first dissociation limit are recorded using degenerate four wave mixing. These spectra are combined with earlier work involving laser induced fluorescence, absorption spectra and Fourier transform emission spectra, to enable a rotational analysis and deperturbation of vibrational levels of the B state up to v′ = 16. Numerous perturbations were noted within the B 3Σ- state, and the origin of these is discussed. In a number of cases, these perturbations can be attributed to interactions with specific other electronic states of SO, such as A 3Π, C 3Π, d 1Π, and A″ 3Σ+.
- Electronic spectroscopy