How does a holographic mid-air laser emitting display work..

[Dom]

Hi, ever since I was a teenager and watching star trek I was always facinated on how a holographic display could actually work. I have made a few designs back in 2000 of a complete concept which in theroy work and i actually sent it off to MIT University a few days ago. The point of my interest in this is not to make money but to help bring it out for everyone. Like 8 years ago would of been great, but I guess things don't move to fast in the world we live in.

I was basically trying to ask them if its possible to bend laser light backwards and sideways and such. I guess one of the last methods for transmitting a holographic field was to use a magnetic field and a chemical to change the laser path to shorten and stop the light from an exit path.

What I have been wondering is if anyone in the photonic scientific field has developed a laser light to transmit a stream of full color and breaks of transparent light, where the transparent light would be the exit path and the full color stream would be the hold image of the holographic picture. I'm not really sure how the MIT mark iii works but from vauge youtube videos it could only do one color and i think they had to use some kind of holo fim to transmit the 3d information.

Along with that to scatter and displace the laser into an image could'nt we just use a glass object or mechanical driven outerfield metric volume space wheel or even some kind of array displacer to volume out the laser image into a well defined cubic space.
I'm not a scientist but I do have an understanding on how to put things together and corrilate. I'm just looking for the right answers.

Anyone know what i am taking about or have a good understanding on how a holographic display should work?

[Okta]

Im betting holograms remaining for most as science fiction. The only (crappy) holograms i know of use lasers to effect gas molecules into colour with very fast focusing beam to draw images in the gas cloud.

[cybereality]

Well holograms are real science, and I actually worked with them a bit in the past. However they need a physical medium (aka film) to imprint the interference pattern. You would still need to be looking at a screen of sorts. It is not like the movies where the hologram projects into empty space. I don't think they have that capability, and I am not even sure that is possible.

There are fog based displays, which may be closer to what you are seeking, but they have next to nothing to do with real holography:

[youtube]http://www.youtube.com/watch?v=yzIeiyzRLCw[/youtube]

[WiredEarp]

@ Okta - those arn't real holograms. They are just pictures painted on a 3d medium (as I see CR has already pointed out).

Holograms are interference patterns that code an entire 3d object. Because you are viewing by looking at or through the 'film', they have serious difficulties with motion.
They are a totally different concept to most other display/capture technologies (a really damn cool one), with some awesome effects, such as the fact that a broken piece of a hologram can be used to view the entire original hologram (hence the 'holo' bit meaning 'whole'). They can 'appear' to be in mid air, but this (I think) is more like the 'popout' on a 3d screen... you need to either look through the film or have it behind the apparent object.

I do wonder however, if you could use 2 laser beams, of different (invisible) frequencies, that would intersect at a certain point and cause a visible light interference pattern at the intersection. If this was possible, you could create a holographic type display by simply scanning the intersection zone across the viewing area, using it as a 3d positioned pixel...

[Okta]

I do wonder however, if you could use 2 laser beams, of different (invisible) frequencies, that would intersect at a certain point and cause a visible light interference pattern at the intersection. If this was possible, you could create a holographic type display by simply scanning the intersection zone across the viewing area, using it as a 3d positioned pixel...

This is what i was talking about. I cant find the link but the lasers focussed on a point causing it to ignite and making a green 3d hologram.

[cybereality]

There is also a 360 degree display based on lasers and a spinning mirror:

[youtube]http://www.youtube.com/watch?v=YKCUGQ-uo8c[/youtube]

And then there stuff projected on glass, which is not 3D but fun none-the-less:

[youtube]http://www.youtube.com/watch?v=JZg6t6WdtyE[/youtube]

[Dom]

In the design I made on paper, I made it so that you have four casing boxes that look purddy and the user is to have them placed in a shape of a square or rectangle in the desired viewing spot. Like where you would place your monitor or tv set. Each of the four casings would have a laser inside it along with the other components.

But I never knew that intersecting laser light would cause a color change. So all that you would need is four casing possibly something else and a color laser for each casing like 1=casing red, 2=casing blue, 3=casing green 4=casing yellow. Thats a good idea but I really wanted a design like mine, so that a user could have a different input source on each casing. So you could have four input devices on a holo tv at once.

I still like the idea of just fast scanning a volume cubic area without the lasers actually changing each others color interference. I wonder how blurry that would be or if at all. Maybe some distortion?

Of course it would have to be safe laser light and not the burning stuff or it would turn into a camp fire.

@Cybereality I think those types of simulated holographics are cool, but are'nt they just using projectors? I think all they are doing is making the 3rd dimension from a 3rd and fourth projector onto a screen. I know you were talking about using a fibre optic cable to transmit a 3d image to a laser too.

Will a laser actually shoot a whole image or will it only display a single light? I know its possible to get a laser to scan an area in hz too, but if you could have a laser behind a lcd shutter screen to convert and magnify the full laser light color into a cubic area then you would not need to fast scan the cubic area.

I'm not sure if you need film to get the proper real time information. I always thought you could get the information from a cpu processor and convert that information into an image processor like a lcd then pass that image to a converter to the laser and have the laser scan the area. If not then just having all the cpu image information goto the laser and have it scan the area directly. Technically if done right the laser system could be moving so fast with the other components to give a mid-air hologram even motion without the need of holofilm. If holofilm was needed I guess instead you could use a transparent lcd screen aka full color lcd shutter and have software layout the 3d pixel information guided to the lasers.