And finally, monsieur, a wafer-thin hologram ... Sir, it is only wafer thin A group of scientists has developed the “world’s thinnest hologram” – a thousand times thinner than a human hair, they claim. Holograms are three-dimensional images created by the interactions of laser lights, and appear to have more depth than images formed from lenses. The dream is that one day, flat images from screens …
Could someone explain how holograms would make sense in small devices? Real holograms don't "project" anything, they are more like windows that show the apparent 3D object, but this image cannot be larger than the substrate of the hologram itself. There are other ways to create 3D images that can be viewed without glasses from different angles, but these involve lighting up "voxels" in some medium, like mist or a translucent block, and these are not holograms.
Somebody should explain to Min Gu how a hologram works. It can not produce an image beyond the bounds of the screen. You can't project an image onto a retina from a point source either (unless your image happens to be a point). That means you're back to glasses or goggles for virtual immersion.
A hologram watch would be mostly useless. The greater the Z-axis, the narrower the viewing angle before tall and deep objects tip from view off the edge of the screen. Let me know when I can wall mount a giant holographic display.
As far as I know, what we call "holograms" in the real world don't just float in mid-air, they invariably need some sort of (transparent) "projection screen" the size of the image you want to project. I am not aware of any technology that can create images apparently floating in mid-air without something being there - at the very least some sort of mist or boundary layer that can act as a "screen". So frankly I have no idea what this is even supposed to be about...
I think the largest example of a rear-screen hologram projection would be the 2013 Magical Mirai show at Yokohama Arena. Even the Nippon Budokan show two years later wasn't as big. ( a good example at https://www.youtube.com/watch?v=cM9cASiuyGg ). At least you don't have to use VR goggles or your cellphone like 1stPLACE Co. seems to use for their IA/ONE live shows.
The earliest used a piece of film, so were static. I first saw one in 1969. The hologram surface is like a window. You can see anything you could have seen at the original scene, so you can see all of a chessboard by moving your head, even though the straight on view might show only a few pieces.
We have no idea how to do images like the original Star Wars projection done by R2D2.
Holography needs a huge bandwidth. We can do "real" 3D computer generated images by scanning an angled ground glass disk rotating fast enough, with R, G and B lasers. It's not holographic, full colour 3D viewable inside a clear cylinder. The effective Z resolution increases the normal flat X Y bandwidth considerably for any decent resolution. Another problem with the rotating disk method is that if there is a wide viewing angle the view is very translucent.
I've no idea what this is or how it can create an image above the surface (but caption does say a fake image!).
Some 20 years ago I saw a hologram in which an american football player ran a few yards as you tilted the hologram, which IIRC was about the thickness of old 120 film. I was gobsmacked by it but couldn't think of any use for it other than maybe advertising. I'm guessing the designer hasn't either.
I dread to think what life will be like when someone finally works out how to make lcds on a sub-wavelength scale so we can create holograms on the fly. As you point out bandwidth needed would be huge and there appears to be a physical law that the script intelligence content is the the inverse of the bandwidth.
Some 20 years ago I saw a hologram in which an american football player ran a few yards as you tilted the hologram
You might be thinking more of lenticular_printing, rather than a proper hologram. You can get a few frames on and it's the movement that gives the illusion of depth
you can make it appear above a surface so long as the surface is still behind the image it is for this reason that smaller screens tend to use depth instead i.e the image appears below the surface. So in the article's image the top part of the glove that is above the background screen would be absent. Now if you could create computer controlled hologram contact lens then you could make for truely convincing holograms.
The fact is that we do not have true 3D vision we just get the idea of depth via various cues and experience which can be themselves tricked, see optical illusions.
@Mage; As far as I'm aware, while traditional "full" holograms give you full viewing movement and parallax in all directions ("like a window") they need to be viewed in fixed-wavelength laser light, which is obviously quite limiting.
The more common "rainbow hologram" sacrifices vertical parallax for the ability to view them in ordinary white light.
They still appear 3D because you have horizontal parallax (stereoscopic vision relying on this), you just don't get the full range of movement.
"Holography needs a huge bandwidth."
Or a pair of dividers and some plexiglass.
Never underestimate hacker ingenuity.
WAY to miss the point... DO tell, how long did it take you to make those 'holograms'??
say about 100 to 200 dots that took a lot of patience, say about 15 minutes of your life wasted, when a proper process would do that in a few seconds... THAT is 'bandwidth' - the time it takes to do something... how many dots do you think are in that star wars LP??? thousands??
and also notice it has been done ages ago, you have to 'look into' the glass that the hologram is in..
well, plenty of them here..
https://youtu.be/7YWTtCsvgvg
BUT... *what* is your definition of a 'hologram'???
MY one is a picture , that will change its axis, as you walk around it...
the above youtube does not show this, just a projection onto plastic, so it looks like it is 'floating'..
a REAL hologram..
"you could see a small chip, with a magnifying glass floating above it. If you looked from above, you were looking 'through' the glass, and saw an enlarged image of the chip"
- if you moved slightly, it magnified a DIFFERENT part of the chip... :)
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* Not that I really NEEDED one, but still...
"An optical resonant cavity allows the light from laser beams to bounce around and reflect many times to create waves that are in different phases. The shifted positions of the light are more likely to create the illusion of depth seen in holographic imaging."
I am now more educated than I was. Thank you.
(Unless you can in the deep UV end of the spectrum, in which you probably need a mask and costume)
It's made by making a "phase" or thickness hologram in the film by blasting away dots of the film with a laser. dots are 2 micrometers square at 800nm. 3mm x 3mm takes 1500 x 1500 pixels. It's made on Silicon so I guess it's viewed in reflection.
You can view the hologram by illuminating it with light at RGB wavelengths. I'm not sure if you illuminate it with 3 beams simultaneously you get the 3 images to line up.
So they've demonstrated quantum effects in the film that lets a film 1/7.4 to 1/10 the thickness of the illuminating light act as a hologram to light at that frequency. But you can't erase it or rewrite it.
Rewritable holograms have been done with plastic films (heat them to soften) or crystals (Pockels Read Out Memory PROM) using a laser write/high voltage erase cycle.
Apart from the quantum science aspect my reaction is "So what?" They've show the phenomena works on this material but the write method is b**ger all use in any sort of display. IOW it's v 0.1 tech.
For those who study quantum mechanics of materials or the construction of "metamaterials" with novel refractive index properties this is no doubt very impressive.
The fantasy of holographic displays is a flat unit you can lay down somewhere and get a large full colour display in front of you. But most computer applications need primarily that to be a 2d image. That puts a lot of data in 1 plane of that image and that plane is at 90deg to the emitter.
People have made cell phones with micro projectors in them to do that.
How well did they sell?
When I was at secondary school back in the 80s we went to a trip to a hologram exhibition in Bristol. It was the most amazing thing I'd ever seen, there were behind the glass holograms so realistic you had to go around the side to make sure you weren't looking at something in a glass box. There was one of a woman's bottom hung from the ceiling, and of course everyone ran around to see her from the front, but it was the same from both sides! Even more incredible were the in front of glass ones, the best being one of the Milky Way, you could walk into the stars and look down in to a virtual hole to see map of the solar system, it blew me away.
These were all proper laser illuminated holograms costing many thousands of pounds, and the only thing you could buy at the time was a rainbow hologram not even as detailed as you get on credit cards these days. But I'm really disappointed that in the 30+ years since that proper holograms haven't become more mainstream, and I've never seen another exhibition like it.
I think the main reason is safety, cost, and the limited nature of the pictures... It is not that easy to make a 1 hour long movie using the process...
then lasers are *dangerous* - for any good display, they are carefully monitored to prevent it hitting your eye, causing blindness or worse...
Cant remember exactly where it was, but the best one i saw (quite small scale) was a computer chip, under a magnifying glass. From the side, you could see a small chip, with a magnifying glass floating above it. If you looked from above, you were looking 'through' the glass, and saw an enlarged image of the chip.
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