True three dimensional TV that does not depend on wearing strange glasses could be demonstrated within five years. Scientists have at last started to catch up with the 3D holographic displays that have become commonplace in science fiction films. The Princess Leia figure projected by R2-D2 in Star Wars is one example of moving holograms that have been shown in a wide range of films over the decades since the invention of holography in the 1960s. How a 3D holographic image would be displayed by the screen But the reality has lagged far behind and for decades relied on using glasses to feed a slightly different image to the right and left eyes, using different coloured lenses or polaroid, for instance in the first film of the "golden era" of 3D movies, Bwana Devils. The glasses remain in use today, for instance to view an Imax version of Harry Potter and the Order of the Phoenix. Now a new material that will allows an updateable palm sized 3D holographic display is described in Nature by Dr Savas Tay, Prof Nasser Peyghambarian and colleagues at the University of Arizona, Tucson, in work that raises hopes for applications in the home, defence, medicine and industry. Red ghostly displays produced by the team, which includes members of the Nitto Denko Technical Corporation, Oceanside, California, show a car, brain molecule and skull in three dimensions. Dr Tay says that if all goes well, a prototype holographic TV system could be available in five years.
Holograms are interference patterns of light generated by the interaction of a uniform reference laser beam with a second beam that has been reflected from an object of interest. If a beam similar to the original reference beam is the shone through a hologram, the result is a three-dimensional image of the object scanned. Just as a moving picture is actually a series of stills shown in quick succession, so a moving hologram would be a series of still holograms to fool the brain.