ATOM-OPTICAL PROPERTIES OF A STANDING-WAVE LIGHT-FIELD

The focusing of atoms to nanometer-scale dimensions by a near-resonant standing-wave light field is examined from a particle optics perspect ive. The classical equation of motion for atoms traveling through the lens formed by a node of the standing wave is derived and converted to a spatial trajectory equation. A paraxial solution is obtained, which results in simple expressions for the focal properties of the lens, u seful for estimating its behavior. Aberrations are also discussed, and an exact numerical solution of the trajectory equation is presented. The effects on focal linewidth of angular collimation and velocity spr ead in the atomic beam are investigated, and it is shown that angular collimation has a much more significant effect than velocity spread, e ven when the velocity spread is thermal.