DIGITAL OPTICS TECHNOLOGIES INC — National Aeronautics and Space Administration SBIR Phase I: S1

Description

Atom interferometry offers the potential to deliver high-performance, compact, and robust gyroscopes that are suitable for inertial navigation.nbsp; Critical requirements for such a gyroscope include a high sensitivity to rotations, insensitivity to accelerations, and a simple scheme that is well-suited to miniaturization.nbsp; An atomic gyroscope based on the combination of point source interferometry (PSI) and large momentum transfer (LMT) beam splitters is well-suited to meet these requirements.nbsp; A conventional PSI is based on the use of cold atoms released from a trap, and subjected to two-photon Raman transitions that act as beam splitters and mirrors for a Mach-Zehnder light-pulse atom interferometer.nbsp; In a PSI, the rotation signal is observed by monitoring the fringes develop across the spatial profile of the expanded cloud, and is unaffected by acceleration.nbsp; The spacing and the orientation of the fringes are analyzed to determine the components of the rotation vector that are orthogonal to the laser pulses, thus realizing a multi-axes gyroscope.nbsp; The sensitivity of a conventional PSI is limited by the relatively small area enclosed, since the conventional Raman pulses produce a momentum separation equivalent to only two photon recoil momenta.nbsp; Under this proposal, we will investigate the feasibility of realizing a PSI that makes use of the technique of large momentum transfer (LMT) based on pulsed Bragg Transitions (BT) and adiabatic rapid passage (ARP).nbsp; For experimentally feasible parameters, such a gyroscope may enclose an area as large as one square centimeter.nbsp; For ten million atoms interrogated per second, it would be able to achieve a rotation sensitivity of about 2.5 micro-degree/hour per root-Hz, which would be nearly a factor of 50 better that the best atom interferometric gyroscope, which is large and based on atomic beams, demonstrated to date.nbsp;nbsp; The LMT-PSI can be compact, and holds the potential for revolutionary advancement in inertial navigation.