One-dimensional laser cooling of an atomic beam in a sealed vapor cell

We describe a simple experiment that demonstrates one-dimensional laser cooling in a sealed vapor cell. A velocity selective optical pumping scheme was first used to define a collimated beam of atoms within the cell. A particular velocity group of atoms was labeled by optical pumping with one laser and detected by absorption with a second laser. Transverse cooling of this velocity group, which formed an atomic beam between the two laser beams, was then observed by applying a third laser beam, in analogy with transverse cooling of a conventional atomic beam.