Compensation of motion-induced atom-laser misalignment errors in an atom-interferometry gravimeter

Atomic gravimeter based on atom interferometry has become a hotspot of quantum optics applications in recent years and shown rapid progress in static-scene measurements. Improving the adaptability on dynamic scenes is an important development direction, which calls for in-depth research on various errors caused by carrier motions. This work focuses on the error evaluation and compensation of motion-induced misalignment between the Raman laser beam and the atomic trajectory. A theoretical analysis framework is formed to investigate the atom-laser misalignment errors by considering both the inhomogeneous Raman laser intensity and wavefront phase distributions in a dynamic perspective. The influence on fringe contrast and phase shift in an atom-interferometry gravimeter is discussed. Quantitative study has been done with different motion types, motion rates as well as random motion noises. The results show oscillational decay trends of fringe contrast with the motion amplitude and the increased significance of rotationally antisymmetric Zernike terms in dynamical Raman wavefront phase shift evaluation. Strong correlations can be found between the misalignment errors and the experimental parameters. A compensation method is proposed accordingly via quickly adjusting the Raman intensity or pulse duration and comprehensive Raman wavefront characterization. Both amplitude and phase corrections are achieved. The analytical approach and results provide a practical solution for further advances of atom-interferometry under harsh motional conditions.