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[1/2]₀, 6p[3/2]₂, and 6p[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-Xe* interaction potentials. An analysis of the line wings under the quasistatic approximation has permitted the extraction of the difference potentials for 3.75≤R≤8.0 {}. 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.