arXiv:1412.6754 · Journal of Physics B Atomic Molecular and Optical Physics
Inhomogeneous broadening of optical transitions of 87 Rb atoms in an optical nanofiber trap
J Lee, Jeffrey A. Grover, Jennifer E. Hoffman, Luis A. Orozco, S. L. Rolston
Abstract
Abstract We experimentally demonstrate optical trapping of atoms using a two-color evanescent field around an optical nanofiber. In our trapping geometry, a blue-detuned traveling wave whose polarization is nearly parallel to the polarization of a red-detuned standing wave produces significant vector light shifts that lead to broadening of the absorption profile of a near-resonant beam at the trapping site. A model that includes scalar, vector, and tensor light shifts of the probe transition - from the trapping beams, weighted by the temperature-dependent position of the atoms in the trap, qualitatively describes the observed asymmetric profile and explains differences with previous experiments that used Cs atoms. The model provides a consistent way to extract the number of atoms in the trap.