Light-shift spectroscopy of optically trapped atomic ensembles

Abstract

We develop a method for extracting the physical parameters of interest for a conventional dipoletrapped cold atomic ensemble. This technique uses the spatially dependent ac-Stark shift of the trap itself to project the atomic distribution onto a light-shift broadened transmission spectrum. We develop a model that connects the atomic distribution with the expected transmission spectrum. We then demonstrate the utility of the technique by deriving the temperature, trap depth, lifetime, and trapped atom number from data that was taken in a single shot experimental measurement.

Loading and spatially-resolved characterization of a cold atomic ensemble inside a hollow-core fiber

“…These results show that the atomic number density distribution is also in our HCPBGF well-represented by Eq. ( 2), i.e., the density is highest on the fiber axis as observed in [27], in contrast to other predictions [14,49], which favored ring-shaped distributions.…”

“…where n 0 is the peak density and T < T F is the ensemble temperature inside the deep FORT. Therefore, spectroscopy of the atoms while the FORT is on will yield information on the FORT depth, density distribution and temperature [14,27]. We recorded absorption spectra with the FORT switched on during the measurement [see Fig.…”

“…( 1)- (2). This leads to a radially-dependent absorption and shift of the levels and we require integration over the radial coordinate in a similar fashion as in [27] for obtaining the transmission through the fiber. We obtain good agreement with the experimental data for an atomic temperature of T = 250 µK for a calculated T F = 900 µK.…”