Two-Photon Two-Color Diode Laser Spectroscopy of the Rb 5D5/2 State

T.T.Grove, V.Sanchez-Villicana, B.C.Duncan, S.Maleki* and P.L.Gould
Department of Physics, U-46, University of Connecticut, Storrs, CT 06269-3046 USA
*Department of Physics, Union College, Schenectady, NY 12308 USA

Published in Physica Scripta, Vol. 52, 271-276, 1995.


We report on spectroscopic measurements of the Rb 5D5/2 state performed using two-photon excitation with a resonant intermediate state. With the two beams (5S1/2 -> 5P3/2 at 780 nm and 5P3/2 -> 5D5/2 at 776 nm) counter-propagating, the spectra are Doppler-free and the signals are very robust, even in a room temperature vapor. This is due to the near match of the transition wavelengths. The 5D3/2 hyperfine constants have been measured and compared to previous determinations. We have also performed the excitation in a sample of laser-cooled atoms and compare these results to those obtained at room temperature. The fact that the 5P3/2 -> 5D5/2 transition is narrow, robust, diode-laser accessible, and relatively immune to AC-Stark shifts, may make it a promising candidate for a frequency reference at 776 nm.