Pressure broadening of Rb D{sub 1} and D{sub 2} lines by {sup 3}He, {sup 4}He, N{sub 2}, and Xe: Line cores and near wings

We studied the line shape of Rb ${D}_{1}$ and ${D}_{2}$ resonance lines in the presence of 1--10 amg of several gases: ${}^{3}$He, ${}^{4}$He, N${}_{2}$, and Xe. We found that the line cores are well described by the asymmetric line shape expected for a van der Waals interatomic potential. The width and shift of the lines is proportional to the density of the foreign gas with high degree of accuracy, while the asymmetry is independent of the density. The constants of proportionality for pressure broadening and shift were measured with much higher accuracy than in previous experiments. We also studied the density dependence of the oscillator strength of the transitions.