Trapping of Ultracold Atoms in a Hollow-core Photonic Crystal Fiber
  Ultracold sodium atoms have been trapped inside a hollow-core optical fiber. The atoms are transferred from a free space optical dipole trap into a trap formed by a red-detuned gaussian light mode confined to the core of the fiber. We show that at least 5% of the atoms held initially in the free space trap can be loaded into the core of the fiber and retrieved outside. 
Caleb A. Christensen, Sebastian Will, Michele Saba, Gyu-Boong Jo,   Yong-Il Shin, Wolfgang Ketterle, David Pritchard