Determining the tilt of the Raman laser beam using an optical method for atom gravimeters  

作　　者：Hua-Qing Luo Yao-Yao Xu Jia-Feng Cui Xiao-Bing Deng Min-Kang Zhou Xiao-Chun Duan Zhong-Kun Hu 骆华清;徐耀耀;崔嘉丰;邓小兵;周敏康;段小春;胡忠坤(MOE Key Laboratory of Fundamental Physical Quantities Measurement&Hubei Key Laboratory of Gravitation and Quantum Physics,PGMF and School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China;Oak Ridge National Laboratory,Tennessee,USA)

机构地区：[1]MOE Key Laboratory of Fundamental Physical Quantities Measurement&Hubei Key Laboratory of Gravitation and Quantum Physics,PGMF and School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China [2]Oak Ridge National Laboratory,Tennessee,USA

出　　处：《Chinese Physics B》2024年第12期264-268,共5页中国物理B（英文版）

基　　金：Project was supported by the National Key Research and Development Program of China(Grant No.2021YFB3900204)。

摘　　要：The tilt of a Raman laser beam is a major systematic error in precision gravity measurement using atom interferometry.The conventional approach to evaluating this tilt error involves modulating the direction of the Raman laser beam and conducting time-consuming gravity measurements to identify the error minimum.In this work,we demonstrate a method to expediently determine the tilt of the Raman laser beam by transforming the tilt angle measurement into characterization of parallelism,which integrates the optical method of aligning the laser direction,commonly used in freely falling corner-cube gravimeters,into an atom gravimeter.A position-sensing detector(PSD)is utilized to quantitatively characterize the parallelism between the test beam and the reference beam,thus measuring the tilt precisely and rapidly.After carefully positioning the PSD and calibrating the relationship between the distance measured by the PSD and the tilt angle measured by the tiltmeter,we achieved a statistical uncertainty of less than 30μrad in the tilt measurement.Furthermore,we compared the results obtained through this optical method with those from the conventional tilt modulation method for gravity measurement.The comparison validates that our optical method can achieve tilt determination with an accuracy level of better than 200μrad,corresponding to a systematic error of 20μGal in g measurement.This work has practical implications for real-world applications of atom gravimeters.

关 键 词：atom interferometer absolute gravimeter precision measurement tilt of Raman laser 

分 类 号：O314[理学—一般力学与力学基础] O562[理学—力学]