Fig. 3: Imaging with alternating beams.
With alternatingly pulsed beams, the stochastic recoil causes atoms to spread out when the imaging duration is increased, as simulated in the upper panel of (a), where colors represent different simulated traces. To compare the experiment with the simulation, we measure the spot size of our atoms. b is an exemplary image averaged over 30 single-shot images where we expand the accordion lattices to 6 μm spacing and perform free space imaging for 7.2 μs. The image is slightly asymmetric since the beams are along one direction and our objective has aberrations especially when the atom randomly walks out of the focal plane. The image is then cropped into individual sites and 1D profiles are obtained by summing over either the x or y axis. The x and y spot sizes are different since the imaging beams are along only one axis and the objective aberrations are anisotropic (SI). The spot sizes with different accordion lattice spacings and imaging durations are shown in (c). The measured spot sizes of the x and y profiles are plotted with circles with error bars. The respective colored lines correspond to the simulated spot size along the x and y directions. The measurements qualitatively agree with the simulation.
