A Real, Laser-based 3D Display

3D display technology is fairly limited. Most 3D displays out there rely on either prisms refracting light from a normal flat-panel display, or shooting lasers into some sort of space-filling device. A few researchers in Japan went with a more unconventional method of making a 3D display that actually lives up to the promises of the displays seen in Star Wars.

From the coverage of this display we’ve found, the green laser demonstration is a scaled-down version that uses water as the display medium. There’s a short clip that shows a red, green, and blue laser projecting a few white voxels into mid-air. The video of both these demonstrations is a bit jumpy, but that’s probably because of the difference in frame rate between the display and camera.

We’re not really sure how the “plasma excitations of air molecules with focused beams” actually work, or even how to control 50,000 of these dots at 15 frames per second. If you’ve got any idea how to build one of these guys, leave a note in the comments.

43 thoughts on “A Real, Laser-based 3D Display

  1. A version of this appeared at SIGGRAPH a few years ago. Definite contender for the whacko mad scientist award. Bright blue sparks floating in mid air, really LOUD arc-welder style buzz, the guys showing it off decked out in heavy safety goggles next to signs with radiation and ozone warnings.

    Maybe containing it makes it slightly more practical.

      1. No, this works by ionizing the air at the focal point of the laser. Goggles are needed for the laser light and ozone warning because ionized air will create ozone and other noxious gasses like NO and NO2.

  2. Once I saw something about a concept to use microwave beams from multiple emitters focused upon a single distant point to destroy a target. The idea being that the individual beams wouldn’t be powerful enough to damage anything in their path alone, only having enough intensity at the focal point.

    I wondered back then if perhaps you could use a similar principle to heat air at a specific point in space. That could be how this system works. In that case “plasma excitations of air molecules with focused beam” would actually mean “exciting air molecules into a plasma using focused beams”.

  3. this reminds me of cataract lasers. they are used by opthalmologists to create a tiny explosion in a predefined area of space in the eye. This is the exact same ionization effect. when you fire these opthalmologic lasers, it sparks a small point of light in the middle of the air where the laser is focused to such a high intensity that the air ionizes and sparks. This little spark is used to “clean” the eye. This must be using this same technology at a very fast rate.

    1. Yea, this seems a lot like laser plasma display (rather than electric arc plasma). If they can solve the issue of power (which can be done later in the case of portables, now for larger concept works), and contaminant/convection issues (in case of free volume, right now that uses fixed volume of purified water), then we’ll be one step closer to the movie type future displays.

  4. The ‘spark’ type display would be reliant on using air as the medium. When two very nearby areas of air are highly ionized, you get what is basically a static discharge between these areas, and a ‘spark’.

    In the water display, heavy ionization would produce electrolysis causing the water to break into hydrogen and oxygen. These ‘bubbles’ reflect a greater percentage of the laser light, and show as ‘points’ of light.

    It is possible, depending on the size of the ‘bubbles’ and the gas/liquid combination that the ‘bubbles’ themselves may become miniature externally-pumped lasing chambers due to total internal reflection and refraction index differences, making them significantly brighter in appearance.

  5. To do this they use two lasers tuned so that when the beams intersect, the energy at that point is high enough to ionize the air, creating a voxel. They just sweep the lasers in the correct pattern (and possibly turn them on or off) to create the desired image.

  6. Funny thing this.

    I defined this exact technology back in the late 80’s, anbd tried to pitch it to Sony & Yamaha among others.
    Under the name SQ/AR (spatial quadrature / amplitude relationship) – it was originally devised to capture and reproduce 3D audio, but at the time, the processing power wasn’t quite up to the task.
    Nowadays audio would be easy. In the original documentation, I made clear reference to using miltiple lasers / plasmaguns in a triangular pyramid configuration to effectivelky create the display shown here.

    If iI recall, I may have lodged a provisional patent back at the time,but didn’t have the means to develop it in my own space – so these guys probably can’t claim an original innovation patent due to prior art… but it’s nice to see it being realised at last.

    Good work!

  7. I’m far from sure but isn’t there that wierd effect with lasers that aren’t absolutely coherent that causes the beam to break up at intervals?
    I’ve only ever heard of it with really highpowered lasers but it’s the first idea that came to mind.
    If you can create a beam that breaks down at the right place you’d be able to create one pixel. Perhaps that would explain the 50k pixel/15fps resolution.

    1. I would bet they’re using a single high-powered laser and galvo scanners to position it. In a super-dense gas or fluid, it wouldn’t take much ionization to cause a state change of some sort.

      I think the princess-leia-hologram effect is pretty neat, with the stray green glow. Now they just need to do it with a 450nm laser to get the movie effect.

    1. as far as i can tell the emitted light is dependant on the laser being used,
      wihtout a uv reactive medium in the right mix (you would need a minimum of 3, one for each color)
      it wouldnt work, defeating the whole purpose of a screenless 3d display (meaning no contained air or vapor or anything, as this project promises in its final iteration)

      if this isnt the case it would indeed be a very good idea to use uv or infrared lasers

      1. I thought that, as several people said above, that the laser caused some kind of ionization and spark, and thats what produces the light, I thought the green glow was just from stray laser light, if this so then the wavelength of the laser is irrevelant, and a nonvisible laser would take care of the problem of the stray light, but since its a spark it would be monochrome. Of course if I’m wrong about the way it works then who knows whats going on. Anyway I guess 3D tv is comming.

    2. it mentions using a red green and blue laser for making a white voxel, a common color mixture.

      it could be that the actual color is determined by stray laser light but if that is the case couldnt that in itself be used for color displays?
      using its imperfections for a purpose

  8. This is exactly how i’d envisioned a 3D display with a base would work,
    just think how they create those ‘3d portraits in cubes of glass’

    two lasers heat up and create a marked area when they cross!

  9. its bull.
    if you listen to the video clearly, it states that the small version was created by shining the lasers INTO WATER and that is how they get the display to be so compact, so really it is actually using the water as a screen.
    They then go on to say with ‘really high power lasers’ it is possible to get the same effect in air at a greater distance.
    Chances are they need the water to cut down on the dangerous reflection of the laser into any ones eyes who are watching the display(remembering of course that if you can see the laser light , it is already damaging your eyes).

    1. Because water is well known as not being transparent…

      In the same way that if you can see the light from a torch it’s damaging your eyes. If you are looking at concentrated beams of laser light or stray reflections of one, then you are at risk. If it’s a dispersed beam then it shouldn’t be at all dangerous. If I look into a beam that’s focussed to a 1mm spot, I’m blind. If the same beam is dispersed over a 360 degree sphere then it’s not really brighter than an equivalent wattage light bulb.

  10. I think the location depends on how long the laser is pulsed for. I have no idea though. This is pretty sick. Can’t wait to get one installed for Chess in my Millennium Falcon.

  11. Could it be that the laser was actually boiling the water and then reflecting off of the microscopic bubbles?

    Also, I can’t be sure, but could the in-air display be white, not because of RGB lasers, but because of the color of the ionization spark?

  12. This is all nice and stuff, but even with a refined method no body is going to start production on a huge water based display for the consumer market..

    I’ll wait for the one that uses air molecules without a density..

  13. I have been doing research regarding the creation of a laser 3d hologram for many years now. This is not the plasma induced hologram that was seen a few years back coming out of japan. This is simply focusing a visible laser on a refracting medium (ie water vapor). This type of hologram is fairly common and can be seen as having existed for the past few years. On of the big leaps about inducing plasma to generate “dots” is that it did not rely on a medium and could in fact be used in open air. However the laser required was a q switched yag laser and would be harmful to anyone in the surrounding area. There is a way to generate a dot in the air without inducing a plasma or ionizing a medium. But if I told you that then it wouldnt be as cool.

  14. call me when theres a company thats developing this. i wanna buy stock~
    and a lightsaber pocketknife!

    and i wanna goto the most power hungry movie theater known to man with big rotating imax sized 3d images and 360 degree stadium seating. instead of 3d glasses they give you welding helmets when you walk in. when you buy popcorn its unpopped… until they power up the screen -=PPPPYYYEEEOOOOOWWwwww=- 50,000 kernels in perfect synchronization *Pop!*. sit back and enjoy the buttery future ;D

    or, i mean, umm… cure cancer with it? somehow?..SHH!! the movie is starting!

  15. Looks like it might work using ultrasound to generate a pressure gradient at a level inside the water tank.
    By adjusting the relative phasing of the ultrasound the gradient’s location can be changed so only 2-D scanning is needed by the laser to get 3-D breakdown anywhere in the tank.

    Wonder if the OP has considered my idea of using 3 different coloured dyes suspended in a solvent then rapidly pumping them through the tank sequentially to get colour?
    You’d need a continuous supply as once mixed they would be no good again..
    However the waste fluids could be recycled if quantum dots were used as the luminescent centres and separated out again using a centrifuge.

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