Laser-Excited Fluorescence Spectra of Yttrium Monoiodide.

Abstract Fluorescence spectra of strontium monoiodide excited by Ar ++ and Kr + laser lines have been analyzed by Fourier transform spectrometry. Rotational levels have been populated either directly or after collisional relaxation: (i) in D 2 Σ + ( v = 0, 1) by ultraviolet lines of Ar ++ , inducing numerous fluorescence transitions ending in the levels v = 0–3 of the strongly interacting A 2 Π and B 2 Σ + states, (ii) in A 2 Π 3/2 ( v = 0–4) by Kr + line at 676.44 nm, de-exciting into transitions to X 2 Σ + ( v = 0–6). Deperturbed constants for A 2 Π and B 2 Σ + states and A ∼ B interaction parameter are calculated from the numerical treatment of D 2 Σ + ( v = 0, 1) → A 2 Π ( v = 0–3) ∼ B 2 Σ + ( v = 0–3) transitions. Rotational constants for D 2 Σ + ( v = 0, 1) are obtained for the first time. The wavenumbers of some 670 fluorescence lines are cataloged.