Comparative analysis of phase noise for different configurations of Bragg lattice for an atomic gravimeter with Bose-Einstein condensate

Abstract

We perform a comparative study of the phase noise induced in the lasers used for Bragg diffraction in a Bose-Einstein condensate-based quantum gravimeter where the Bragg beams are generated using two different configurations. In one of the configurations, the Bragg beams that form the moving optical lattice are generated using two different acousto-optic modulators. In the second configuration, the Bragg beams are generated using a single acousto-optic modulator carrying two phase-locked frequencies. The second configuration shows a suppression of the phase noise by a factor of 4.7 times in the frequency band up to 10 kHz, the primary source of noise, which is the background acoustic noise picked up by optical components and the optical table. We report a short-term sensitivity of 1360 mu Gal/root Hz and upon integration over 200 s, achieve a resolution of 99.7 mu Gal for an interferometric duration of 10 ms.