Abstract

Results of high flux atom interferometry experiments with potassium in generalized Talbot-vonLau configurations are presented. The interferometer consists of a sequence of three planar vacuum slit diffraction gratings, microfabricated from silicon nitride membranes. Interference fringes are sensed by measuring the transmission of atoms on a hot-wire as a function of grating relative position. Different spatial Fourier components (up to fifth) in the diffraction pattern are resonant in the interferometer at different atomic velocities. When a laser cooled slow beam is incident, various different diffraction patterns are observed as a function of atomic velocity, selected via the tuning of D2 cooling lasers. In an alternative “Heisenberg Microscope” configuration an incident thermal beam produces a velocity average over different fringe Fourier components. Fringe patterns for each HFS component are revealed by their selective destruction by AC modulated weak Dl laser light passing through the interferometer near the middle grating. Since imaging of the fluorescent light could determine which slit an atom passes, the laser removes the fringe pattern contribution by Doppler shifted atoms at its wavelength. That contribution is thus AC modulated and detected. Shifts of the patterns by gravity and rotation are evident when the vacuum chamber is tilted.

© 1993 Optical Society of America