Hybridization of an Absolute Quantum Gravimeter with a Homemade Interferometric Sensor for Ground Motion Compensation

Absolute quantum gravimeters based on atom interferometry achieve outstanding accuracy and long-term stability, but their operation in real-world environment critically depends on an efficient compensation of ground vibrations, generally provided by auxiliary classical sensors. These sensors are most often commercial devices, which can limit flexibility and system optimization.

In this work, we present the development of a homemade inertial sensor designed to be coupled with the absolute quantum gravimeter of Exail [1]. We demonstrate the successful hybridization of an atomic gravimeter with an interferometric inertial sensor. This constitutes a proof of concept for the direct interfacing of an atomic sensor with a laboratory-developed classical sensor.

The inertial sensor is an interferometric accelerometer operating in the 0.01–100 Hz band. It consists of a leaf-spring suspended proof mass with a natural frequency of 2.8 Hz and a compact mechanical structure. The proof-mass motion is measured using a custom homodyne quadrature Michelson interferometer, providing a displacement resolution of 2 × 10⁻¹³ m/√Hz at 10 Hz. These characteristics allow the sensor to meet the requirements for vibration compensation in atom-interferometric gravimetry.[2]

We describe the mechanical and electronic integration of the interferometric sensor within the gravimeter.
Experimental results show that the gravimeter remains operational when driven with the homemade sensor, demonstrating the robustness of the hybridization and validating the overall concept. Although further improvements are required to the targeted gravity measurement performance,  these results open a clear path toward customizable hybrid quantum–classical gravimetric systems.

[1] Ménoret, V., Vermeulen, P., Le Moigne, N. et al. Gravity measurements below 10−9 g with a transportable absolute quantum gravimeter. Sci Rep 8, 12300 (2018)
[2] A. Amorosi, L. Amez-Droz, M. Zeoli, B. Thibaut, M. Teloi, M.H. Lakkis, A. Sider, C. Di Fronzo, C. Collette. (2025)
On broadening techniques for a high-resolution optical accelerometers. In Sensors and Actuators.