Physical Review Letters
Two-Photon Near-Resonance Light Scattering from an Atomic Level
J. Liran, L. A. Levin, G. Erez, Joshua Jortner
Abstract
We have studied the time-resolved spectra, the energy-resolved spectra, and the total intensity of light emission induced by near-resonance two-photon excitation to the $4^{2}D_{\frac{3}{2}}$ and $4^{2}D_{\frac{5}{2}}$ levels of Na over the detuning range $\ensuremath{-}7 {\mathrm{cm}}^{\ensuremath{-}1}<~\ensuremath{\Delta}<~7 {\mathrm{cm}}^{\ensuremath{-}1}$. The time-resolved spectra of Na perturbed by Ar exhibit a fast adiabatic component and a slow resonance-fluorescence component. The cross section for phase-shifting, ${T}_{2}$-type collisions in this atomic system is $\ensuremath{\sigma}=110\ifmmode\pm\else\textpm\fi{}20$ ${\mathrm{\AA{}}}^{2}$.