$\lambda /4$, $\lambda /8$, and higher order atom gratings via Raman transitions
Abstract
A method is proposed for producing atom gratings having period $\lambda /4$ and $\lambda /8$ using optical fields having wavelength $\lambda $. Counterpropagating optical fields drive Raman transitions between ground state sublevels. The Raman fields can be described by an effective two photon field having wave vector 2 k, where k is the propagation vector of one of the fields. By combining this Raman field with {\em another} Raman field having propagation vector 2 k, one, in effect, creates a standing wave Raman field \label{91}%which whose ``intensity'' varies as $\cos (4 k\cdot r).$ When atoms move through this standing wave field, atom gratings having period $\lambda /4$ are produced, with the added possibility that the total ground state population in a given ground state manifold can have $\lambda /8$ periodicity. The conditions required to produce such gratings are derived. Moreover, it is shown that even higher order gratings having periodicity smaller than $\lambda /8$ can be produced using a multicolor field geometry involving three (twophoton) Raman fields. Although most calculations are carried out in the RamanNath approximation, the use of Raman fields to create reduced period optical lattices is also discussed.
 Publication:

arXiv eprints
 Pub Date:
 January 2002
 DOI:
 10.48550/arXiv.physics/0201017
 arXiv:
 arXiv:physics/0201017
 Bibcode:
 2002physics...1017D
 Keywords:

 Physics  Atomic Physics
 EPrint:
 12 pages, 4 figures