Effective velocity distribution in an atom gravimeter: effect of the convolution with the response of the detection

Tristan Farah (1) , Pierre Gillot (1) , Bing Cheng (1) , Arnaud Landragin (2) , Sébastien Merlet (1) , Franck Pereira dos Santos (1)

1 LNE - SYRTE - Laboratoire national de métrologie et d'essais - Systèmes de Référence Temps-Espace
2 SYRTE - Systèmes de Référence Temps Espace

We present here a detailed study of the influence of the transverse motion of the atoms in a free-fall gravimeter. By implementing Raman selection in the horizontal directions at the beginning of the atoms free fall, we characterize the effective velocity distribution, ie the velocity distribution of the detected atom, as a function of the laser cooling and trapping parameters. In particular, we show that the response of the detection induces a pronounced asymetry of this effective velocity distribution that depends not only on the imbalance between molasses beams but also on the initial position of the displaced atomic sample. This convolution with the detection has a strong influence on the averaging of the bias due to Coriolis acceleration. The present study allows a fairly good understanding of results previously published in {\it Louchet-Chauvet et al., NJP 13, 065025 (2011)}, where the mean phase shift due to Coriolis acceleration was found to have a sign different from expected.

Mots clés: atom gravimeter; atom interferometry

Domaines: Physique Atomique [physics.atom-ph]

Tristan Farah, Pierre Gillot, Bing Cheng, Arnaud Landragin, Sébastien Merlet, et al.. Effective velocity distribution in an atom gravimeter: effect of the convolution with the response of the detection. 2014. ⟨hal-01011010⟩