Eur. Phys. J. D 48, 171-176 (2008)
https://doi.org/10.1140/epjd/e2008-00109-0

Measurement of the Rb D2 transition linewidth at ultralow temperature

Physics Dept., Petrie Bldg., York University, 4700 Keele St., M3J 1P3, Toronto, Canada

Corresponding author: ^a wlaser@yorku.ca

Received: 11 January 2008
Revised: 8 March 2008
Published online: 6 June 2008

Abstract

The Rb D2 linewidth was studied using atoms cooled to a temperature of 50 μK that were contained in a magneto-optical trap. The transmission of a probe laser through the atom cloud was monitored using a CCD detector. The frequency of the probe laser was scanned across the resonance using an acousto-optic modulator. The observed lineshape was very well fitted by a Lorentzian function. The full width half maximum linewidth was examined as a function of the optical depth and the probe laser intensity. The extrapolated value at zero optical depth 6.062 ± 0.017 MHz corresponds to a 5P_3/2 lifetime of 26.25 ± 0.07 ns. This result agrees with lifetimes found in experiments that measured the temporal decay of fluorescence or photoassociation spectroscopy and is somewhat below the result of a relativistic many body perturbation calculation.