Gray scale atom holography

We have demonstrated the generation of a black-and-white atomic pattern by using a thin-film computer generated hologram. To extend this technique for the generation of a more complicated gray-scale pattern of atoms, however, considerable improvement is necessary in two points. For a black-and-white holography a single atom is sufficient to express a point on the imaging surface. Therefore, the number of atoms that is required to draw a pattern with the N /spl times/ N resolution is approximately N/sup 2//2 atoms.