Excitation transfer between the rubidium 5 2 D fine-structure levels in collisions with ground-state rubidium atoms: Experiment and theory

We report a study of fine-structure mixing Rb(5 2 D 5/2 )→Rb(5 2 D 3/2 ) in collisions with ground-state Rb atoms. In the experiment, two-photon cw laser excitation was applied to the Rb vapor cell. The measured cross section for the process was (5.8Ϯ1.9)ϫ10 Ϫ14 cm 2 . Theoretical calculations using nonadiabatic collision theory gave a value of 3.4ϫ10 Ϫ14 cm 2

Spectral Study of Caesium Dimer Excited with 476.5, 472.7, 465.8 and 457.9 nm Argon Ion Laser Lines

The results of a study of Cs$\text{}_{2}$ fluorescence excited by different blue lines of the Ar$\text{}^{+}$ laser are reported. Special attention was paid to the analysis of the narrow fluorescence band at 522 nm. Approximate assignments of the fluorescence transitions were obtained. The origin of the observed fluorescence is discussed and a rough reconstruction of a fragment of the E'(3)$\text{}^{1}$Π$\text{}_{u}$ upper-state potential curve is presented and found to be nearly parallel to the corresponding portion of the ground-state X$\text{}^{1}$Σ$\text{}^{+}$$\text{}_{g}$ potential curve

Lifetime and Collisional Depopulation Cross Section for the 142\text{}^{2}D3/2\text{}_{3}\text{}_{/}\text{}_{2} State of Rb

The lifetime τ and the cross section σ for depopulation induced by collisions with ground-state Rb atoms were measured for the 14$\text{}^{2}$D$\text{}_{3}\text{}_{/}\text{}_{2}$ state of Rb. The experiment was performed in the gas-cell conditions in a range of Rb vapour temperatures in the vicinity of 340 K. The lifetime value τ = 1970(130) ns, agrees with the theoretical prediction with allowance for the influence of blackbody radiation as well as of the effects due to core polarizability and spin-orbit interaction. The measured cross section σ = 6.5(3.1) × 10$\text{}^{-12}$ cm$\text{}^{2}$ is close to the geometrical cross section. This agrees with similar observations made by other authors for the case of the lower n$\text{}^{2}$D states of Rb

Spectral and Time-Resolved Studies of Green Cs2\text{}_{2} Fluorescence

The origin and dynamic properties of the green fluorescence of Cs$\text{}_{2}$ excited by laser lines in the 457-488 nm range are studied. Emphasis is placed on the analysis of the 501-527 nrn range. The identified fluorescence line progressions are attributed to the E'(3)$\text{}^{1}$П$\text{}_{u}$ → X$\text{}^{1}$∑$\text{}^{+}$$\text{}_{g}$ transition. An extension of the attractive branch of the E'(3)$\text{}^{1}$П$\text{}_{u}$ potential towards longer inter-nuclear distances is reconstructed by the semi-classical method. A narrow feature at 522 nm is found to be connected with a minimum of the difference potentiał. The lifetime values are measured. The multicomponent fluorescence decays are interpreted as evidence of perturbations of the E'(3)$\text{}^{1}$П$\text{}_{u}$ state by a number of bound and repulsive states of dicherent symmetry. The predissociation rates are estimated

Inelastic cross-sections and natural lifetimes for the 6

The results of an experimental study of population dynamics following excitation of $\rm 6^2D_{5/2, 3/2}$ and $\rm 8^2S_{1/2}$ states of rubidium are reported. Excitation transfer and quenching cross-sections in collisions with ground state rubidium atoms, and natural lifetimes have been measured. The experiment was performed in a vapour cell, using pulsed two-photon excitation and photon counting detection. The analysis of time dependent signals was based on a rate equation model in which transitions induced by thermal radiation have been accounted for. The measurements yielded following results: (1) $\rm 6^2D$ state J-mixing cross-section: $\rm \sigma_{6D_{5/2} \rightarrow 6D_{3/2}}^{Rb-Rb} = 9.2(2.1) \times 10^{-14} cm^2$; (2) cross-sections for $\rm 8^2S\rightarrow 6^2D$ excitation transfer process: $\sigma^{\rm Rb-Rb}_{8{\rm S}\rightarrow 6{\rm D}} = 3.4(1.2) \times 10^{-14} {\rm cm}^2$; (3) quenching cross-sections: $\sigma^{\rm Rb-Rb}_{q, 8{\rm S}} = 12.8(3.4) \times 10^{-14} {\rm cm}^2$, $\sigma^{\rm Rb-Rb}_{q, 6{\rm D}_{3/2}} = 22.8(2.9) \times 10^{-14} {\rm cm}^2$, $\sigma^{\rm Rb-Rb}_{q, 6{\rm D}_{5/2}} = 14.1(5.7) \times 10^{-14} {\rm cm}^2$; (4) radiative lifetimes: $\tau_{8\S} = 161(3)$ ns, $\tau_{\rm 6D_{3/2}} = 256(4)$ ns, $\tau_{\rm 6D_{5/2}} = 249(5)$ ns