Noise Resilience in a High-Bandwidth Atom Interferometer

The utility of inertial sensors depends on resilience against real-world dynamics and noise. Atom interferometry offers a sensing technology with the advantage of good long-term stability, high sensitivity, and accuracy. High measurement bandwidth improves an atom interferometer's ability to reject errors due to dynamics and noise. Here we demonstrate resilience against time-varying environmental noise by rapidly switching the direction of inertial sensitivity in the atom interferometer through a common technique known as k-reversal. We demonstrate sub-interrogation-time k-reversal at 592 Hz in a cold-beam atomic interferometer with an inverse interrogation time of 148 Hz. The interferometer fringe output is read out continuously and post-processed using nonlinear Kalman filters to determine both the inertial and error contributions to the output phase. The resulting power spectral densities show a significant reduction of phase error due to a noisy magnetic field as the k-reversal frequency increases.