We present a theoretical proposal and simulation study of a digital closed-loop thermal atomic-beam interferometer for inertial navigation applications. The scheme synchronizes phase biasing with momentum-kick reversal through the atomic transit time, extracting four interferometric phases to suppress Raman beam path-length errors, while two-photon detuning feedback maintains a pseudo-inertial frame and eliminates cross-coupling. The interferometer enables simultaneous measurements of acceleration and rotation based on an absolute, atom-interferometric reference, with high bandwidth and a wide dynamic range. Numerical simulations verify that acceleration and angular velocity can be measured simultaneously and independently in real time without cross-coupling, demonstrating the absolute, decoupled nature of the proposed measurement scheme. We further evaluate the noise-limited performance of the sensor and obtain sensitivities of 3μm/s2/Hz (velocity random walk) and 15μdeg/h (angular random walk) for a 170∘85Rb beam and an interferometer arm length of 100~mm, surpassing the performance of sensors currently used in state-of-the-art inertial navigation systems.
Abstract : In this article, we review the basic physics of an atom interferometer. We highlight the usefulness of atom interferometers for inertial navigation due to their high phase sensitivity to both linear acceleration and angular rotation, but also the drawback that a single atom interferometer cannot distinguish between the two sources of phase shifts. We describe a design for a dual atom interferometer to simultaneously measure acceleration and rotation and we describe the current status of our apparatus.