Developing a compact gravimeter for field measurements

Atomic gravimeters are used to accurately measure gravity by detecting the quantum interference patterns of freely falling atoms in a vacuum. However, these devices are typically bulky and complex, limiting their real-world use. Seo et al. designed, built, and tested a compact, field-deployable atomic gravimeter.

Atomic gravimeters are typically based on magneto-optical traps that use lasers to trap and slow atoms for precision sensing. The researchers’ device is based on a grating magneto-optical trap, which achieves this with a single input beam, making it significantly smaller. The grating magneto-optical trap allowed the authors to simplify the trapping geometry and optics of the gravimeter as well as reduce its overall size.

The authors confirmed that the compact device operated reliably and met performance standards of conventional atomic gravimeters. The system was able to take high-precision gravity measurements at the microgal level, which is enough to resolve subtle changes in gravity for geophysics and engineering applications, with stability over extended operation.

This system could be used for long-term gravity monitoring in the field, such as detecting mass changes in subsurface water, volcanic activity, or subsidence.

“This combination of high stability, compactness, and robustness represents a significant step toward routine gravity measurements outside specialized laboratories,” said author Sang-Bum Lee. “Our work helps bridge the gap between laboratory-grade quantum sensors and practical gravimetric tools for applications such as groundwater monitoring, resource exploration, infrastructure assessment, and navigation.”

Next, the authors will decrease the power consumption and environmental sensitivity of this gravimeter, as well as further reduce its size.

“We also plan to integrate it into mobile platforms and networks of sensors to enable spatially distributed gravity measurements,” Lee said.

Source: “A field-deployable compact gravimeter based on a grating magneto-optical trap with µGal-level long-term stability,” by Sangwon Seo, Hyun-Gue Hong, Jae-Hoon Lee, Sang Eon Park, Taeg Yong Kwon, Sanglok Lee, Jeongju Choi, Meungho Seo, Jongcheol Park, and Sang Bum Lee, Applied Physics Letters (2026). The article can be accessed at https://doi.org/10.1063/5.0307253 .