物理学报2025，Vol.74Issue(3)：80-91,12.DOI:10.7498/aps.74.20241348
一种面向原子干涉仪均匀量子非破坏测量的光学环形腔
Optical ring cavity for homogeneous quantum nondemolition measurement in atom interferometer
摘要
Abstract
High-finesse optical cavity assisted quantum nondemolition(QND)measurement is an important method of generating high-gain spin or momentum squeezed states,which can enhance the sensitivity of atom inter-ferometers beyond the standard quantum limit.Conventional two-mirror Fabry-Perot cavities have the draw-back of a standing wave pattern,leading to inhomogeneous atom-light coupling and subsequent degradation of metrological gain.In this study,we present a novel method of achieving homogeneous quantum nondemolition measurement by using an optical ring cavity to generate momentum squeezed states in atom interferometers.We design and develop a high-finesse(F=2.4(1)× 104),high-vacuum compatible(1× 10-10 mbar)optical ring cavity.It utilizes the properties of traveling wave fields to address the issue of inhomogeneous atom-light interaction.A strontium cold atomic ensemble is prepared and coupled into the cavity mode;the nondemolition measurement of atom number is achieved by extracting the dispersive cavity phase shift caused by the passage of atoms through differential Pound-Drever-Hall measurement.Experimental results indicate that under a probe laser power value of 20 μW,the dispersive phase shift of the ring cavity is measured to be 40 mrad.The effective number of atoms coupled into the cavity mode is around 1 × 105.The consistency between the ring cavity dispersive phase shift and QND measurement theory is verified by adjusting parameters such as matching the atomic position with the cavity mode and tuning the frequency of the probe laser.The optical ring cavity developed in this work provides an important method for generating spin or momentum squeezed states in atom interferometers.Therefore it holds promise for enhancing their sensitivity,and it is expected to be widely applied to cavity-enhanced quantum precision measurements.关键词
光学环形腔/量子非破坏测量/自旋压缩/原子干涉Key words
optical ring cavity/quantum nondemolition measurement/spin squeezing/atom interferometer引用本文复制引用
王恩龙,王国超,朱凌晓,卞进田,莫小娟,孔辉..一种面向原子干涉仪均匀量子非破坏测量的光学环形腔[J].物理学报,2025,74(3):80-91,12.基金项目
国防科技大学电子对抗学院青年博士基金(批准号:KY22C211)和国防科学大学青年自主创新基金(批准号:ZK23-47)资助的课题. Project supported by the Youth Doctoral Fund of College of Electronic Engineering,National University of Defense Technology,China(Grant No.KY22C211)and the Youth Autonomous Innovation Fund of National University of Defense Technology,China(Grant No.ZK23-47). （批准号:KY22C211）
