Filtered Talbot lens: Producing $\lambda /2n$-periodic atomic patterns with standing wave fields having period $\lambda $

摘要

We propose a scheme to create high-contrast, periodic atom densitydistributions having period $\lambda /2n$ using the Talbot effect, where $%\lambda $ is the wave length of the optical fields that scatter the atoms and$n$ is a positive integer. This {\em filtered Talbot lens} is comprised of twostanding-wave optical fields. An atomic beam propagates perpendicular to thefields. The first field, which is far-detuned from the atomic transitionfrequency, acts as an array of lenses that focuses the atoms. The second field,positioned at the atom optical focus of the first, is resonant with the atomictransition frequency and acts as an amplitude mask, leaving unperturbed onlythose atoms that pass through its nodes. At distances following the interactionwith the second field that are equal to an integral fraction of the Talbotlength, atomic density gratings having period $\lambda /2n$ are formed.