Fig. 3: Single shot shear-Ramsey interference in orbit.

a Fringe spacing λ_fr of a shear-Ramsey interferometer aboard CAL as a function of the free-evolution time t_TOF of the BEC after release from the magnetic trap. The BEC is split coherently with two π/2 Bragg pulses each lasting 0.16 ms with a separation of 1.0 ms between them to achieve the characteristic interference pattern for both exit ports within a single experimental run. The measured fringe spacings (blue dots for data and dashed line for the fit) show excellent agreement with the theoretical prediction (purple line) based on the expansion dynamics of the BEC in the Thomas–Fermi regime and a proper treatment of the finite pulse duration as expressed by Eq. (2). Exemplary 2D-density distributions for two different expansion times are shown in the top row (189 × 189 μm² area, with densities normalized for each image individually) with the integrated 1D densities (black lines) displayed below together with the fit results (red lines). b The contrast of the interference fringes (green dots) increases with expansion time and saturates at a maximum of around 45%. Error bars represent 1-sigma confidence bounds of fitting the density distributions.