ATOMIC INTERFEROMETRY GYROSCOPES, ACCELEROMETERS, AND GRAVITY GRADIOMETERS

摘要

The invention is a neutral atom (and/or molecule) matter-wave interferometer (and/or set of interferometers) that can be used as an inertial sensor with a sensitivity exceeding that of conventional mechanical sensors and multiple circuit optical interferometers (including ring lasers) by many powers of ten. An interferometer in which matter-wave propagation beam paths enclose a finite area will sense rotations via the Sagnac effect. One with the paths displaced from each other will sense acceleration plus gravity. Interferometers with paths that follow a figure-eight pattern yield a gravitational gradiometer. Laser cooling and slowing of a beam of neutral atoms provides a low energy nearly monochromatic source. Diffraction gratings are employed as beam splitters. Such gratings may consist of apertures in a sheet of solid material, near-resonant standing-wave laser beams, or crystal faces. Path curvature due to acceleration and rotation is canceled by magnetic and/or electric field gradients that produce an effective levitation of slow atoms. A feedback system that maintains an interferometer phase null is employed with its error signal yielding the inertial effect signals. Magnetic and/or electric fields are used for producing matter-wave phase shifts. The invention may be used to measure acceleration, rotation, position, orientation, gravity, the mass distribution of nearby matter, and an electric current. Other important applications are mass tomography, geodesy, and petroleum exploration.