Thread: Creating holograms from dots of photons?

Hi,

I was wondering if it is possible to say shoot two particles, first one and then another one at slightley greater speed so that when they collide (the second one catched up with the first) create a short lived dot of visible light?

Why am I wondering this you might ask...
Well I was talknig to a friend about sci-fi movies and we really wondered when someone would create the kind of holograms that we see so often.
My idea for this was to have one or several very fastley rotating "emitter" that can shoot two particles that when collide creates a photon.
The delay of the second particle would create a collition at a certain distance and the emitter would though software change angle, combine these two and you have 3d coordinates.

This would allow the device to create dots (3d pixels of sort) of visible light at certain distances and angles and in that way creating a hologram that dosn't need to be projected on anything.

Would this be possible?
If so what do I need to build one ?

Interesting idea but I can't see any way to implement it.

And, just to be picky, you are talking about a 3D display technology, rather than a hologram (which isn't quite the same thing).

It is already possible to create computer generated holographic images. Obviously, these are not 3D as they can't be viewed from any angle (but do give a true stereoscopic effect over a limited range).
Computer-generated holography - Wikipedia, the free encyclopedia

Photons don't readily collide nor can you shoot them at varying speeds.

I've thought about a very similar idea before though using a medium that would allow two photons to collide with it at once and release a single photon with the combined energy. Then you can aim two IR lasers the would create a visible dot at their intersection. You could use banks of lasers to increase the frame rate. If you could find the right kind of material, you could even use three lasers to pick out a single point in 3D space, making it a true 3D display. (Stacking a number of 2D planes might be easier though. On the other hand, if you needed 3 lasers to light up a point, undesirable collisions could be reduced.)

Of course, there are still all kinds of technical (and probably theoretical) problems with this idea. I have no idea if such a material exists and even if it did, I'd be surprised if it worked at more than one precise frequency (which would give a monochrome display) especially as the material would need to be nearly transparent to visible light. Also, I have no idea if it's even theoretically possible for the resulting photon of visible light to scatter, so it might not be viewable from all angles. Then there's the problem (worse in the 3D version) that you'd be able to see through the glowing dots to those in the back.

Still, it may not be impossible.

Originally Posted by MagiMaster

Photons don't readily collide nor can you shoot them at varying speeds.

I've thought about a very similar idea before though using a medium that would allow two photons to collide with it at once and release a single photon with the combined energy. Then you can aim two IR lasers the would create a visible dot at their intersection. You could use banks of lasers to increase the frame rate. If you could find the right kind of material, you could even use three lasers to pick out a single point in 3D space, making it a true 3D display. (Stacking a number of 2D planes might be easier though. On the other hand, if you needed 3 lasers to light up a point, undesirable collisions could be reduced.)

Of course, there are still all kinds of technical (and probably theoretical) problems with this idea. I have no idea if such a material exists and even if it did, I'd be surprised if it worked at more than one precise frequency (which would give a monochrome display) especially as the material would need to be nearly transparent to visible light. Also, I have no idea if it's even theoretically possible for the resulting photon of visible light to scatter, so it might not be viewable from all angles. Then there's the problem (worse in the 3D version) that you'd be able to see through the glowing dots to those in the back.

Still, it may not be impossible.

These materials exist. Actually most materials have some nonlinear properties but usualy very weak. The thing is for this mechanism to work (it`s called double frequency generation or sum frequency generation) you have to meet phase matching condition (basicaly conservation of momentum and energy) that is usualy met only at one specific angle for outgoing beam. Nonlinear optics probably won`t help with this problem nor do I see any other viable mechanism. Best we have for 3d imaging is simple holography IMHO.

How come I don't know much about holograms(perhaps how they can be produced)#