Hologram Directs Atom Lithography

A team at Universität Bonn and Universität Osnabrück, both in Germany, has combined holography and atom lithography to control the selective etching of a carbon-coated gold surface. The technique, which is described in the Feb. 25 issue of Physical Review Letters, promises to ease the fabrication of photonic crystals.

Previously, researchers had constructed exposure masks for atom lithography with laser beams, but creating complex patterns would require complicated optical systems. In the demonstration, the team recorded a three-beam interference pattern in an Fe:LiNbO₃ crystal with a 2-W Ti:sapphire laser. Upon readout, the crystal produced an interference region that focused a beam of cesium atoms onto the target.