Abstract

Three 0.2-μm period diffraction gratings were used to realize an atom interferometer,¹ A three-grating geometry was used with the interfering beams distinctly separated in both position and momentum. An interaction region, consisting of a stretched metal foil positioned symmetrically between two side electrodes, was inserted in the interferometer so that the atom waves in the two sides of the interferometer went on opposite sides of the foil. The foil was 10 cm long and 10 μm thick, and the gap between the foil and each electrode, where the separated beams traveled, was 2 mm. We used a well-collimated beam of sodium atoms with a deBroglie wavelength of 16 pm. The fringe amplitude was 820 cps, which allows us to determine the phase to 15 mrad in 1 arcmin (Fig. 1).

© 1993 Optical Society of America