Practical applications of the 5DJ levels of Rb include their role in portable, vapor-cell atomic clocks [1] and the definition of the meter [2]. I will outline a recent experiment where simultaneous measurements of the 5D_{3/2} state’s dynamic polarizability and photoionization (PI) cross section at 1.064 μm are made using laser spectroscopy. In this experiment, cold ^{85}Rb atoms are trapped in a deep, 1.064-μm optical lattice of ~10^5 photon recoils and probed with two lasers scanning over the D1 and 5P_{1/2}-to-5D_{3/2} lines. Detection of the 5D_{3/2} population as a function of the laser detunings is achieved by collecting and counting photo-ions. This procedure yields a dynamic scalar polarizability of -524(17) atomic units and PI cross section of 44(1) Mb.

[1] Kyle W. Martin, Gretchen Phelps, Nathan D. Lemke, Matthew S. Bigelow, Benjamin Stuhl, Michael Wojcik, Michael Holt, Ian Coddington, Michael W. Bishop, and John H. Burke, Phys. Rev. Applied 9, 014019 (2018).
[2] T. J. Quinn, Metrologia 40, 103 (2003).