Fig. 1. (a) Stimulated Raman transition in three-level system and (b) momentum transfer in stimulated Raman transition.

Fig. 2. Structure of Mach–Zender-type atom interferometry.

Fig. 3. Typical process of atom interferometer with parabolic trajectory.

Fig. 4. (a) Polarization configurations in a hollow pyramidal MOT. (b) MOT array in Imperial College London. (c) Experiment setup of pyramidal atom gravimeter using single laser beam in LNE-SYRTE. Panel (a) reprinted with permission from Ref. [59] of the Optical Society. Panel (b) reprinted with permission from Ref. [60] of the Optical Society. Panel (c) reprinted from Ref. [61], with the permission of AIP Publishing.

Fig. 5. Atom chips reported by (a) University of Innsbruck and (b) University of Strathclyde. Panel (a) reprinted with permission from Ref. [65] Copyright (2000) by the American Physical Society. Panel (b) reprinted by permission from Ref. [67] Copyright (2013) by the Springer Nature.

Fig. 6. Fiber optical system using single laser source based on telecom C-band.

Fig. 7. (A) Measurement route, (B) gravity anomaly as a function of the elevation. (C) Atomic gravimeter inside a vehicle. (D) The atomic gravimeter apparatus. Reprinted by permission from Ref. [42]. Copyright (2019) by the AAAS. (© The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC) http://creativecommons.org/licenses/by-nc/4.0/).

Fig. 8. Picture of cold atom gravimeter installed on a gyro-stabilized platform next to a spring gravimeter. Reprinted by permission from Ref. [76]. Copyright (2018) by the Springer Nature.

Fig. 9. (a) Flight plan of Iceland gravity campaign. (b) Comparison between airborne measurements and ground measurements upward continued. Reprinted by permission from Ref. [84]. Copyright (2020) by the Springer Nature.

Fig. 10. (a) Acceleration signal recorded by the MAs. (b) AI discrete measurements. Corresponding to the atomic fluorescence of the ⁸⁷Rb atoms in the F = 2 state, normalized to the fluorescence of all the atoms. (c) and (d) Atomic measurements plotted versus the signal stemming from the MAs at 1 g (c) and 0 g (d). Reprinted by permission from Ref. [87]. Copyright (2011) by the Springer Nature.

Fig. 11. Mach–Zehnder interferometry of a BEC in microgravity as realized in the ZARM drop tower in Bremen (a), where absorption imaging (b) brings out the interference fringes (c). Reprinted with permission from Ref. [99]. Copyright (2013) by the American Physical Society.

Table 1. State-of-the-art in gravimeters based on stimulated Raman transition (1 μGal = 10⁻⁸ m/s²).