New metamaterial gives light a one-way ticket

The light-warping structures known as metamaterials have a new trick in their ever-expanding repertoire. Researchers at the National Institute of Standards and Technology (NIST) have built a silver, glass and chromium nanostructure that can all but stop visible light cold in one direction while giving it a pass in the other. The device could someday play a role in optical information processing and in novel biosensing devices.