Direct imaging of periodic sub-wavelength patterns generated by optical phase masks

We demonstrated direct imaging of interference fringes of total atomic density with period λ/4 and λ/2 for optical wavelength λ that have been produced in de Broglie wave atom interferometer. The imaging was done by means of an ``optical mask" technique, which allowed us to observe sub-wavelength periodic patterns with a resolution of up to λ/16. In addition, the dependence of the fringe pattern on the recoil phase and pulse areas reveals quantum dynamics in the atomic center-of-mass motion. The behavior of the fringe patterns near the interference times distinguishes the effects of phase gratings from those of amplitude gratings.

A. Turlapov, A. Tonyushkin, and T. Sleator, PRA 68, 023408 (2003).

A. Tonyushkin, and T. Sleator, arXiv:physics/0512016 (2005).