Atom interferometry with thousand-fold increase in dynamic range (2005.11400v1)

Abstract: The periodicity inherent to any interferometric signal entails a fundamental trade-off between sensitivity and dynamic range of interferometry-based sensors. Here we develop a methodology for significantly extending the dynamic range of such sensors without compromising their sensitivity, scale-factor, and bandwidth. The scheme is based on operating two simultaneous, nearly-overlapping interferometers, with full-quadrature phase detection and with different but close scale factors. The two interferometers provide a joint period much larger than 2{\pi} in a moir\'e-like effect, while benefiting from close-to-maximal sensitivity and from suppression of common-mode noise. The methodology is highly suited to atom interferometers, which offer record sensitivities in measuring gravito-inertial forces but suffer from limited dynamic range. We experimentally demonstrate an atom interferometer with a dynamic-range enhancement of over an order of magnitude in a single shot and over three orders of magnitude within a few shots, for both static and dynamic signals. This approach can dramatically improve the operation of interferometric sensors in challenging, uncertain, or rapidly varying, conditions.