Measurement of Rb 5P3/2 scalar and tensor polarizabilities in a 1064-nm light field

We employ doubly resonant two-photon excitation into the 74S Rydberg state to spectroscopically measure the dynamic scalar polarizability, alpha(0), and tensor polarizability, alpha(2), of rubidium 5P(3/2). A cavity-generated 1064-nm optical lattice allows us to reach intensities near 2 x 10(11) W/m(2), where the atom field is larger than the hyperfine interaction, and magnetic sublevels are well resolved. In the evaluation of the data we use a self-referencing method that renders the polarizability measurement largely free from the intensity calibration of the laser light field. We obtain experimental values alpha(0) = -1149(+/- 2.5%) and alpha(2) = 563(+/- 4.2%), in atomic units. Methods and results are supported by simulations. The results provide an experimental test of atomic-structure calculations used to determine systematic shifts in atomic clocks and to interpret fundamental-physics experiments.