Demonstration of an ultrahigh-sensitivity atom-interferometry absolute gravimeter

作者:Hu, Zhong-Kun*; Sun, Bu-Liang; Duan, Xiao-Chun; Zhou, Min-Kang; Chen, Le-Le; Zhan, Su; Zhang, Qiao-Zhen; Luo, Jun
来源:Physical Review A, 2013, 88(4): 043610.
DOI:10.1103/PhysRevA.88.043610

摘要

We present an ultrahigh-sensitivity gravimeter based on an Rb-87 atom interferometer using stimulated Raman transitions. Compared with our previous work, a two-dimensional magneto-optical trap is added in the new gravimeter to increase the atom number and improve the detection signal-to-noise ratio, and a better optical phase-locked loop system is used to reduce the phase noise of Raman beams. Benefiting from these efforts and the excellent performance of the active vibration isolator, a short-term sensitivity of about 4.2 mu Gal/root Hz (1 mu Gal = 1 x 10(-8) m/s(2)) is reached, which improves the sensitivity by a factor of 2 compared with the former best reported value. By a modulation experiment, we further indicate that the residual vibration noise contribution is about 1.2 mu Gal/root Hz, which implies a possible improvement over the present absolute gravity measurement level by about one order of magnitude. Moreover, we demonstrate a calibration experiment to directly evaluate the sub-mu Gal resolution of our gravimeter.