The University of Arizona researchers developed a new polymer-based material that encodes information using electric fields. The material contains two components. When light strikes the film, one of these components, a polymer, absorbs photons and generates electrons and their positive counterparts, called holes. The polymer is also a good conductor of holes, but not of electrons. As a result, the holes can easily move away from the illuminated areas where they were generated, whereas the electrons stay put. This separation of charges creates patterns of tiny electric fields within the material. These electric fields change the way that light moves through the different parts of the film.

The second component of the material, a dye, responds to the electric fields in two ways. The dye molecules change their polarization and physically rotate depending on the nature of the fields in each part of the film. These changes locally affect the index of refraction, which has to do with how a material bends and reflects light. When the researchers shine a laser through the film, the dye alters the path of the light, projecting a pattern that the eye interprets as a three-dimensional image. "It comes out of thin air--you feel like you could touch it," says Nasser Peyghambarian, a professor of materials science and engineering at the University of Arizona, who led the work.

To erase the image, the researchers expose the film to uniform light, which redistributes the electrons and holes, removing the electric fields and the changes in the material that they had produced.

Jan Tor, Captain of Interplanetary Patrol Cruiser 79388 in Edmond Hamilton's 1928 novel Crashing Suns, had holographic videoconferencing (he called it a telestereo):

Abruptly I was aroused from my musings by the sharp ringing of a bell at my elbow. "The telestereo," I said to Hal Kur. "Take the controls."

As he did so I stepped over to the telestereo's glass disk, inset in the room's floor, and touched a switch beside it. Instantly there appeared standing upon the disk, the image of a man in the blue and white robe of the Supreme Council, a lifesize and moving and stereoscopically perfect image, flashed across the void of space to my apparatus by means of etheric vibrations. Through the medium of that projected image the man himself could see and hear me as well as I could see and hear him, and at once he spoke directly to me.