Holographic Television and Optical Transistors

Radical Rad writes "This is based off an article from the American Chemical Society Journal and says that 3D TV may be less than a decade away due to an advance made at UCLA which allows portions of crystals to be brightened, darkened, and change colors in nanoseconds using electic and magnetic fields. Light passing through the crystals might then be used to project moving holographic images. The same crystalline material could also be used in optical computers and probably many other applications."

Comments

Projection, but what about camera tech?

[PD]

Nice that we can forsee a way to project holographic images, but is there a corresponding idea for recording holographic images? Maybe the old fashioned stereo camera images would need to be processed into a hologram by a computer.

Resolution and Retensivity

[c0enzyme]

Silver halide and DCG holograms have finer resolutions than the Kodak film most people use. I wonder how the crystal compares. It would only need to create television quality.

Also if the refresh times of the crystal are not fast enough for comfortable viewing, you could do some 3D interlacing. (They do mention color changes in billionths of a second... perhaps they wont run into retensivity problems.)

Do 3D interlacing formats exist? Thay probably use them at SGI and Pixar... im behind the times.

One thing to note is that every frame of the 3D image would be a totally separte 2D interference pattern on the holographic plate. You cant just do a 2D interlace directly on the the holographic plate like you do in TV. That means that you will need to scan the 2 demiensional plate rather quickly, or do it in parallel. I would love to see how they implement the electric and magnetic fields to control the crystal.

How, exactly, would this work?

[breon.halling]

This will probably be modded down quite a bit, but I've always been somewhat perplexed by the concept of holographic projection.

My question is this: On to what would the image be projected? Would there not have to be some kind of screen or bubble on which the image resides?

Is it possible just to have an image floating in mid air?

Hope this isn't a waste of bandwidth! ;)

Cheers,
B.

It's Already Been Done... sort of

[mfago]

Yes, the image is a "virtual" image -- you would have to look though some sort of screen to see the image -- but it _would_ appear to "float" behind the screen.

A hologram can be thought of as acting like a time-shifted "window" onto the scene recorded. If a true full-spectrum hologram was created the light you would see from the hologram would be "exactly" as if you were looking through a window at the subject.

I would think this would work similarly (as stated above), except the different frames would be electronically created in real time. Electronically created colograms are nothing new, but the resolution required is staggering.

I took my optics class at U. Michigan from one of the "fathers" of holography. He showed us some large holograms created in the former USSR that were truly amazing.

He also told us that in the former USSR they made "true" 3D movies by recording holograms of different scenes on a several square-meter piece of film, varying the reference beam angle between frames. By then scanning the reference beam through these same angles in the "theater" the audience looking through the film "screen" would see the movie.