Abstract:
The excitation spectrum of the resonance luminescence of $\mathrm{Na}$ atoms in a mixture with $\mathrm{CF}_4$ exhibits a satellite transition corresponding to the simultaneous optical excitation of the colliding atom and molecule, $\mathrm{Na}({}^2\mathrm{S}_{1/2})+\mathrm{CF}_4(v_3=0)+hv\to\mathrm{Na}(^2\mathrm{P}_{1/2,\,3/2})+\mathrm{CF}_4(v_3=1)$, where ${{v}_{3}}$ is the infrared active mode of CF4 with a vibrational quantum energy of $1283$ cm$^{-1}$. It is shown that the optical coupling between the upper and lower states of this asymptotically $(R_{\text{Na-CF}_4}\to\infty)$ forbidden transition can be explained within a model that takes into account the polarization of the atom in the field of the molecule and the interaction of the dipole moment of the $\mathrm{CF}_4(v_3=1\to v_3=0)$ transition with the dipole moments of electronic transitions in the atom. The results of calculations based on this model are in satisfactory agreement with the experiment. It is noted that $\mathrm{CF}_4$ may be of interest as a component of a working medium of diode pumped alkali lasers.