Holographic method for site-resolved detection of a 2D array of ultracold atoms
We propose a novel approach to site-resolved detection of a 2D gas of ultracold atoms in an optical lattice. A near-resonant laser beam is coherently scattered by the atomic array, and after passing a lens its interference pattern is holographically recorded by superimposing it with a reference laser beam on a CCD chip. Fourier transformation of the recorded intensity pattern reconstructs the atomic distribution in the lattice with single-site resolution. The holographic detection method requires only about two hundred scattered photons per atom in order to achieve a high reconstruction fidelity of 99.9 %. Therefore, additional cooling during detection might not be necessary even for light atomic elements such as lithium. Furthermore, first investigations suggest that small aberrations of the lens can be post-corrected in imaging processing.
KeywordsOptical Lattice Interference Fringe Reference Beam Scattered Photon Atomic Distribution
JHD would like to thank Jürgen Eschner for an interesting discussion on photon scattering. The authors thank all the members of the Institut für Quantenmaterie. This work was supported by the German Research Foundation DFG within the SFB/TRR21.