HOLOGRAMS can now be erased and rewritten, paving the way for 3D television and extending their usefulness in data storage.
Not only do holograms display images in 3D, they can also store digital information that way. Instead of recording bumps on the surface of a disc, they embed the data throughout its thickness, so they can cram a huge amount into a very small space – 300 gigabytes on a CD-sized disc.
Until now the information was stored as chemical changes to a polymer coating, which is irreversible. Researchers at the University of Arizona, Tucson, have now stored it as…
