Dynamic Scalar Polarizability and Photoionization Cross Section Measurements of the Rb 5D_3/2 Level

Knowledge of dynamic polarizabilities is crucial in the development of magic optical traps for extending coherence times in the subfields of quantum information and precision metrology. In the latter subfield, there has been interest in making use of the rubidium 5D states.  We report the first measurement of the dynamic scalar polarizability of the rubidium 5D_3/2 state in a photoionizing optical lattice at 1064 nm using two-photon laser spectroscopy. We simultaneously probe the light shifts on both the D1 line and the 5P_1/2 to 5D_3/2 transitions, a method that calibrates the lattice field intensity the atoms see. This lattice is ultra-deep (~10⁵ photon recoils) and is realized with a near-concentric field-enhancement cavity located within our vacuum chamber. We also report a measurement of the 5D_3/2 photoionization cross section σ at 1064 nm by measuring the linewidths of the spectral peaks. No theoretical values have been established for either physical quantity to our knowledge thus far.