Reflection cooling of sodium atoms in an evanescent light wave

Studied in this work is the cooling of a beam of sodium atoms upon its reflection from an evanescent light wave. The cooling mechanism is associated with the spontaneous transitions of the atoms between the hyperfine-structure sublevels of the ground state. Subject to studies is the relationship between the reflection angle of the atoms and the frequency detuning and intensity of the light wave. It is demonstrated experimentally that the transverse atomic momentum component can be reduced by more than one half (Delta p(perpendicular to)/p(perpendicular to)congruent to 0.5) in a single reflection event, the number of cooled atoms in the reflected beam exceeding 50%. It should be noted that the loss of atoms in reflection can be made as small as desired, and so the reflection cooling cycle can be repeated many times over.