Laser-cooled cesium atoms confined with a magic-wavelength dipole trap inside a hollow-core photonic-bandgap fiber
Taehyun Yoon, Michal Bajcsy
We report loading of laser-cooled cesium atoms into a hollow-core photonic-band gap fiber and confining the atoms in the fiber's $7\text{\ensuremath{-}}\ensuremath{\mu}\mathrm{m}$-diameter core with a magic-wavelength dipole trap at $\ensuremath{\sim}935$ nm. The use of the magic wavelength removes the ac Stark shift of the 852 nm optical transition in cesium caused by the dipole trap in the fiber core and suppresses the inhomogeneous broadening of the atomic ensemble that arises from the radial distribution of the atoms. This opens the possibility to continuously probe the atoms over timescales of a millisecond---approximately 1000 times longer than what was reported in previous works, because the dipole trap does not have to be modulated. We describe our atom-loading setup and its unique features and present spectroscopy measurements of the cesium's ${D}_{2}$ line in the continuous-wave dipole trap with up to $1.7\ifmmode\times\else\texttimes\fi{}{10}^{4}$ loaded inside the hollow-core fiber.
arXiv:1812.02887•Physical Review A•Feb 14, 2019•19 citations