Fluorescence of S2(B–X) excited by fixed frequency ultraviolet lasers

Fluorescence spectra from rotational levels in the B 3Σ−u state of disulfur excited by pumping the ground state with a cw helium–cadmium laser (325 nm) and with a pulsed nitrogen laser (337 nm) have been studied. The He–Cd laser excites the transition (v′ = 3, N′ = 24, J′ = 25) ← (v″ = 3, N″ = 25, J″ = 26), or (3,3)P1(25). A comparison of high resolution spectra of the nitrogen laser and of S2 shows that several transitions in the (2,4) band could be excited: R3(23), P2(13), R2(21), and R3(25).