The world's first reusable 3-D screen debuts, thanks to new photorefractive film that can be written on and erased again and again...

...Researchers at the University of Arizona's College of Optical Sciences (OSC) in Tucson, and engineers from Nitto Denko Technical Corporation, in Oceanside, Calif., recently unveiled a prototype of a photorefractive polymer film on which 3-D images can be recorded, erased and replaced with new images. When carried out swiftly enough, this process leads to a series of images on the film that deliver three-dimensional action that can be picked up by the naked eye.

Conventional holograms--such as the silver bird emblazoned on credit cards to verify their authenticity--are static and have no memory. But "imagine a hologram that is dynamic, where the image is changed frequently," says Nasser Peyghambarian, chair of photonics and lasers at the OSC.

The University of Arizona photorefractive polymer is significant for several reasons, says Joseph Perry, a professor of chemistry and biochemistry at the Georgia Institute of Technology in Atlanta and associate director for photonics at the school's Center for Organic Photonics and Electronics. First of all, he says, it's "updateable"--images can be written, erased and rewritten onto the polymer in much the same way music and video is burned onto CDs or DVDs. "Equally important," he says, is that the researchers were "able to build the display using very basic materials." Dynamic holography has been possible using lithium niobate crystals, but the process of growing these crystals into large display screens is far more difficult and less practical than creating a polymer film...