Abstract

We use optical dipole forces to guide neutral rubidium atoms through hollow- core optical fibers. In one configuration, light copropagates in the circular hollow region as a grazing incidence mode. Atoms are attracted to the high intensity region of a beam detuned to the red of rubidium's D2 resonance Hues and are thus kept away from the fiber's walls. In a second configuration, light is guided in the annular glass region and it is the evanescent field of this light that repels the atoms from the fiber walls when the light is tuned to the blue side of atomic resonance. The glass fiber connects two otherwise separate vacuum chambers. The input side has rubidium atoms at room temperature; the output side is at high vacuum and the atom flux is detected with use of a combination of a hot wire and a channeltron. We have guided atoms in fibers with hollow diameters down to 10 microns and lengths up to 12 cm. A study of the detuming and intensity dependence reveals a number of features. Tor the case of red guiding, at low intensities the dipole guiding potential is purely conservative and the flux profile is approximately dispersion shaped. At high intensities, viscous dipole forces heat the atoms and bum a hole in the flux versus detuning curves.

© 1996 Optical Society of America