Atom Interferometry Progress

An atom interferometer is constructed in which the atom waves are physically separated prior to being recombined. Fabricated transmission gratings are used as optical elements for the matter waves. Atom interferometers should be useful in studies of atomic properties, tests of basic quantum physics, for metrology, as rotation sensors, and perhaps ultimately as devices to make ultra- small structures using atom holograms. During the last year our atom interferometer has evolved from a rough plan to an essentially complete device. At present all the major components of the interferometer have been built, and tested at least once. The system will be given its first real try in the next year. Our interferometer consists of three 0.2 microns - period diffraction gratings equally spaced approx. 0.65 m apart in our atomic beam machine. The maximum separation of the beams will be approx. 60 microns. The first two gratings separate and redirect the atomic beam forming a standing wave interference pattern in the atomic flux at the third grating, which acts like a mask to sample this pattern. A principle technical obstacle is the mechanical vibrations of our machine which will blur the interference pattern.