Two-Dimensional Coherent Splitter For Atom Interferometry

Inertial navigation has been widely used in many fields.High-precision real-time measurement of the rotation speed of the carrier in three directions is of great significance for improving the inertial navigation performance.As a high-precision inertial sensor,atom interferometry gyroscope has been rapidly developed in recent years,and it is considered to have important potential applications in the inertial navigation system.This paper focuses on the two-dimensional coherent beam splitter of the cold atomic matter-wave and the atomic interferometry inertial measurement based on this method.We realized a two-dimensional coherent matter-wave splitter and a two-dimensional atomic interferometer successively.(1)We solved the Schr(?)dinger equation for the system consisting of the atom and two orthogonally propagating Raman laser beam,and obtained the evolution matrices of the two and the three-dimensional coherent beam splitters.We derived the transition probability and the phase shift of the multidimensional atomic interferometer,providing theoretical guidance for the multi-dimensional atomic interferometry experiment.(2)Design and implement the Raman optical systems for two dimensional atom interferometers.The Raman beams with power up to 80 m W and a phase noise lower than-90 d Bc/Hz in the frequency range of 100 Hz-100 k Hz were realized,which can meet the requirement of the Raman beams in two-dimensional atom interferometer.(3)We constructed the two-dimensional matter-wave detection system with Raman spectroscopy by scanning the Raman beam's frequency in two directions independently.The momentum-resolved Raman spectroscopy can distinguish the atom's momentum states,which can provide the information of relative atom number of different quantum states.(4)Raman beams propagating in both horizontal and vertical directions were employed to couple the momentum states of ⁸⁷Rb atom,and the two-dimensional coherent beam splitter for the atomic wave packet were realized.Finally,two atom interferometers with orthogonal Sagnac areas were achieved with contrast of 21%and24%,respectively.This work will be helpful for constructing the high precision multi-axis atom interferometer with large Sagnac area.