Mini G: a simple, precise, and versatile atom interferometer

Gravimeters have been successfully applied for metrology, geology, and mineral exploration. Atomic gravimeters based on atom interferometry are more accurate and have better long-term stability. Compact and transpotable atom interferometers with the ability of multiaxis inertial sensing would open up applications in inertial navigation, such as aviation, robotic aircraft, and other emerging technologies. However, state-of-the-art atom interferometers are too complicated to operate in a miniature package.

With a single diode-laser and a pyramidal magneto-optical trap, we have domenstrated an extremely simple and compact atom interferometer that can measure 3 axes of accelerations, 3 axes of rotations, and 2 axes of inclinations. Only a single diode laser is used for all functions, including atom trapping, interferometry, and detection. With a "magic" single photon detuning, efficient Doppler-sensitive Raman transitions are achieved without velocity selecting the atom sample, and with zero differential AC Stark shift between the cesium hyperfine ground states, increasing signal-to-noise and suppressing systematic effects. The moive shows a free-falling cold atom cloud from the pyramidal mirror. The inertial forces are measured with interferomtry of the free-falling atoms. Now we are upgrading the miniG apparatus and will transport it from a well-controlled laboratory to geophysics fields.

Team members

Xuejian Wu

Zachary Pagel

Bola Malek

Past Team menbers

Jordan Dubley

Philip Canoza

Fei Zi

Ryan J. Bilotta


  1. Multiaxis atom interferometry with a single-diode laser and a pyramidal magneto-optical trap. Xuejian Wu, Fei Zi, Jordan Dudley, Ryan J. Bilotta, Philip Canoza, and Holger Müller, Optica 4(12),1545-1551 (2017) and arXiv:1707.08693.