Cellular News reports:

Imagine having a mobile phone wallpaper which is not a flat image, but a full 3D-Hologram, which can then be updated by the user just as easily as they currently buy replacement wallpapers. That is the promise which could come from a breakthrough by University of Arizona optical scientists.

They have developed a method of "rewriting" holograms, and while the technique is far too slow for live moving images, it would enable static images (such as wallpapers) to be changed on a whim.

The holographic displays – which are viewed without special eyewear – are the first updatable three-dimensional displays with memory ever to be developed, and while the scientists talk in depth about military applications (understandable as the military funded the work), it is the consumer market which will doubtless leap at this new development....

Their device basically consists of a special plastic film sandwiched between two pieces of glass, each coated with a transparent electrode. The images are "written" into the light-sensitive plastic, called a photorefractive polymer, using laser beams and an externally applied electric field. The scientists take pictures of an object or scene from many two-dimensional perspectives as they scan their object, and the holographic display assembles the two-dimensional perspectives into a three-dimensional picture.

New Scientist adds:

The same material could store "pages" of rewritable data in layers through the depth of a hologram, they say. Today's emerging holographic disks are read-only....

With more improvements to the material's optical and electronic properties, [Nasser] Peyghambarian is confident that refresh rates high enough for 3D video displays are possible "within the next few years".

In the meantime, he hopes the technology will prove useful in medical imaging, to instantly screen images of the body that remain viewable for some time.