A lab in Japan has created a new way of making 3D animation by using lasers to create balls of plasma in the air:
Japan's National Institute of Advanced Industrial Science and Technology (AIST) has developed a device that uses lasers to project real three-dimensional images in mid-air. The institute unveiled the device on February 7 in a demonstration that showed off the device's ability to project three-dimensional shapes of white light.
AIST developed the projector with the cooperation of Keio University and Burton Inc. (Kawasaki, Japan). Until now, projected three-dimensional imagery has been "artificial" -- optical illusions that appear 3D due to the parallax difference between the eyes of the observer. Prolonged viewing of this conventional sort of 3D imagery can cause physical discomfort.
The newly developed device, however, creates "real" 3D images by using laser light, which is focused through a lens at points in space above the device, to create plasma emissions from the nitrogen and oxygen in the air at the point of focus. Because plasma emission continues for a short period of time, the device is able to create 3D images by moving the point of focus.
A demonstration of the new technology is pictured above. Perhaps unsurprisingly, creating little balls of plasma in the air creates crackling noises: "Heat from the laser caused the air to expand, producing a crackling sound that resembled a series of tiny explosions."
It doesn't look like the resolution is particularly good, but I am sure that will improve over time. My two concerns are:
1) What if you walk through it? I assume plasma balls are not for touching. It seems like it would be difficult to make it safe.
2) Can you get it to be in color? My suspicion is that the emission spectrum of air would be determined by the composition of the gas. Maybe you could put it in a container and change the composition, but this would only allow you to do one color at a time. Another possibility might be to vary the light from the lasers at different points to get different excitation and emission spectra.
All told, though, a very cool technology.
Hat-tip: Slashdot
I thought of this idea YEARS ago - using multiple crossed high-powered laser beams to create glowing points of localized ionization breakdown in the air. Combined with computerized directional control of the lasers, you could use it to create animated 3D images of any size in thin air, with interesting potential use as an alternative to firework displays and other visuals at outdoor rock concerts, etc.
I should have filed a patent when I first thought of it... :o(
This is very cool.
My old man came up with a similar idea too in the late 90s. He even went out and bought one of those cheap little ionizers, and a couple of laser pointers.
I told him it probably wouldn't work, because of the quantum nature of the photon-atom interaction - crossing the beams doesn't do anything to the wavelength of the photons, so I figured it couldn't be used to control whether a point in the gas flouresced or not. I guess I was wrong.
On the colour question - if the mechanism for the light emission is excited atoms emitting their 'extra' energy(like in the aurora borealis) is it not possible to get more than one colour from any given element, assuming you can control what energy level you excite it to?