Holographic Video

There's a new hope for science-fiction fans who have been waiting for three-dimensional video of princesses to be beamed into their living rooms ever since George Lucas introduced the concept in his 1977 film "Star Wars." A team led by Nasser Peyghambarian, an optical sciences professor at the University of Arizona, reports the first demonstration of technology that can record a scene in one location and replay it as a 3-D hologram at a remote location in almost real time (Nature 2010, 468, 80).

Peyghambarian envisions applications beyond transmitting clandestine messages to retired Jedi knights. The system could be used for telemedicine, manufacturing, entertainment, and 3-D mapping, he says.

"At the heart of the system is a screen made from a novel photorefractive material, capable of refreshing holograms every two seconds, making it the first to achieve a speed that can be described as quasi-real time," according to Pierre-Alexandre Blanche, the study's lead author. The holograms can be rendered in full color and with full parallax—so that the image can be viewed from different perspectives by someone moving around it.

The key material is a copolymer consisting of a polyacrylic backbone with pendant tetraphenyldiaminobiphenyl and carbaldehyde aniline groups. To lower the copolymer's glass-transition temperature, the researchers added the plasticizer 9-ethylcarbazole. They further enhanced the polymer's properties with a fluorinated dicyanostyrene chromophore and used a fullerene derivative—[6,6]-phenyl-C61-butyric acid methyl ester—as a dopant to sensitize the photorefractive material to nanosecond laser pulses.

"By optimizing the chemical composition and glass-transition properties of a class of photorefractive polymers, the researchers have overcome a significant challenge, demonstrating that these types of materials can exhibit the high-index contrast and rapid recording and refresh rates required for dynamic displays," comments Lisa Dhar, an expert on holographic materials who is a senior technology manager at the University of Illinois, Urbana-Champaign.