Arizona researchers have created the first 3-D hologram movie that plays almost in real time, they report in the Nov. 4 Nature. It's the fastest known demonstration of telepresence, where a 3-D hologram depicts a scene from another location.
The key to the invention is a new type of plastic that can refresh the hologram once every two seconds. While that's too slow to watch the World Series in 3-D, the researchers estimated holographic TV could be coming in seven to 10 years.
"It is very very close to reality," says physicist Nasser Peyghambarian of the University of Arizona in Tucson. "Something that was science fiction is something we can do today."
Holograms are created when light bounces off a sheet of material with grooves in just the right places to project an image away from the surface, like on some credit cards. The image is even crisper when the illuminating light waves march in step, as they do in a laser.
Holographic video is already possible, albeit painfully slow -- the U.S. military records enemy territory in 3-D, but refreshing each frame of the video can take an entire day. The Arizona team created a quicker way to play holographic video in 2008, but with that method each frame still took four minutes to generate. Now, after two years of optimizing the plastic, they've cut the time to just two seconds.
Sixteen cameras snap pictures of an object that are piped into a desktop PC, which processes the data. Then the computer shoots the holographic pixels, or "hogels," electronically to another location. There, the hogels are transformed into an optical signal and transmitted by a laser onto a plastic screen, much like a projector shines light onto a white screen to play a movie.
When this light hits, the plastic screen undergoes chemical reactions that temporarily record the most recent set of images in the data stream.
A particular color of light illuminates the plastic and -- voila! Light scatters in just the right way to recreate the original image. Then, the new plastic can be erased, creating a clean slate for the next image.
Read more at Discovery News
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