Ramsey Imaging of Optical Traps

Mapping the potential landscape with high spatial resolution is crucial for quantum technologies based on ultracold atoms. Yet, imaging optical dipole traps challenging because purely methods, commonly used to profile laser beams in free space, are not applicable vacuum. In this work, we demonstrate precise in-situ of by probing a hyperfine transition Ramsey interferometry. Thereby, obtain an absolute map micrometer and shot-noise-limited spectral precision. The idea technique control polarization ellipticity trap beam induce differential light shift proportional potential. By studying response ellipticity, uncover small but significant nonlinearity addition dominant linear behavior, which explained geometric distribution atomic ensemble. Our can find wide application atoms, as it applies multiple species limited particular wavelength or geometry.