Evanescent-wave guiding of atoms in hollow optical fibers

We use evanescent laser light to guide atoms through hollow-core optical fibers. The light, detuned to the blue side of rubidium's $D_2$ resonance lines, is launched into the glass region of a hollow capillary fiber and guided through the fiber by total internal reflection from the glass walls. Atoms interacting with the evanescent component of the field are repelled from the wall and guided through the fiber hollow. A second laser tuned to the red side of resonance is used to initially inject the atoms into the evanescent guide. An optical intensity threshold for guiding is observed as the evanescent-field-induced dipole forces exceed the van der Waals forces.