Two-photon laser spectroscopy of xenon collision pairs

A computer-controlled, frequency-doubled, pulsed dye laser has been used in conjunction with a sensitive and linear photodetection scheme to measure the two-photon absorption profiles of the ground to $6p{[\frac{1}{2}]}_{0}$, $6p{[\frac{3}{2}]}_{2}$, and $6p{[\frac{5}{2}]}_{2}$ two-photon transitions in xenon over a pressure range of a few Torr to 10 000 Torr. Absolute two-photon coefficients are reported. Line-shape measurements of the shift and width of the Lorentzian core allow the deduction of the long-range dispersion terms of the Xe-${\mathrm{Xe}}^{*}$ interaction potentials. An analysis of the line wings under the quasistatic approximation has permitted the extraction of the difference potentials for $3.75\ensuremath{\le}R\ensuremath{\le}8.0$ \AA{}. These short-and long-range difference potentials have been combined and used in an Anderson-Talman phase-shift calculation to reconstruct the absorption profiles. Measurements of the fluorescence following selective laser excitation have been taken and branching fractions for collisional excitation to other members of the $6p$ manifold at a xenon pressure of 100 Torr are reported.