Abstract

The spectral lineshapes of the Sr (5¹P₁–5¹P₀) resonance transition perturbed by rare gases have been examined with a high-resolution laser-induced fluorescence method. In He and Ne, the collisional broadened spectral profiles are found to be symmetrical over the entire studied pressure range (0–600 Torr). The resulting line shapes are accurately represented by a simple Voigt profile expression. The Ar, Kr, and Xe perturbing gases, however, produce anomalous asymmetrical line broadening. To our knowledge, this represents the first measurement of asymmetrical broadening in the near wings of the emission profiles of the Sr-rare gas systems. Quantitative comparisons of the measured and theoretical line asymmetries suggest that atomic interactions in the Sr-rare gas systems are not entirely due to van der Waals (R^-6)-type interactions. The line asymmetries could be caused by the correlations between thermal motions of the Sr atoms and collisional interactions.

© 1992 Optical Society of America