Credit: C. Weitenberg et al. [1]

Figure 1: Measuring the angular distribution of light scattered from cold atoms in an optical lattice. Bosonic rubidium atoms are held in a square lattice with a periodicity of $532nm$. Optical molasses beams (four red beams in the $xy$ plane) at $780nm$ are also incident on the atoms, and scatter light out of the plane (some of the coherently diffracted light is shown). To measure the angular distribution of scattered light, the focal plane of a microscope is placed roughly $20$ microns below the lattice plane. Alternatively, to image the occupancy of the lattice sites, this focal plane would be coincident with the square lattice.