Improving the contrast of a compact atomic gradiometer by optimizing Raman laser power and detuning

Atom interferometry is a precise tool for quantum sensing, with applications ranging from inertial measurements to precision tests of fundamental constants. Compact atom interferometers have been used to develop transportable atomic gravimeters and gradiometers for gravity surveys and mineral exploration. Here, we report a compact atomic gradiometer using two pyramidal magneto-optical traps in a single laser beam. Using a two-photon Raman transition pulse with a Gaussian intensity profile and a square-wave temporal profile, we characterize its efficiency as a function of laser power and single-photon detuning. Furthermore, we investigate the ellipsoidal contrast of the atomic gradiometer and determine the optimal conditions. Additionally, we study the effect of ellipsoidal contrast due to the temperature of the atomic clouds and the short-term noise of Raman laser pulses.