3D Adverts Could Appear Out of Thin Air
Advertising displays could soon appear out of thin air, thanks to a laser system that projects moving 3D images in the sky. The system, developed by Burton of Kawasaki, Japan, focuses a laser pulse onto a point in the air to ionise it, briefly creating a ball of glowing plasma, dubbed a flashpoint. By firing hundreds of laser pulses each second, the system creates the illusion of many constant points of light.
An early version of the system, created in collaboration with teams at Japan's National Institute of Advanced Industrial Science and Technology and Keio University, Tokyo, was unveiled in 2006. It produced 200 flashpoints per second and used a mechanical system to move the laser. This limited it to displaying basic 2D images.
A new laser has increased the firing rate to 1000 flashpoints per second, while the pulses are now directed automatically using optics, allowing the system to create more complex 3D images - and even animations. New images released by Burton include stick figures and a version of the "Utah teapot" - a long-standing reference object in 3D programming.
The company is now investigating the use of the technology for outdoor advertisements, for which they will need to increase the size of the projections - currently less than a metre wide - by using more powerful lasers. It is aiming for a practical device by 2011. Other suggested applications include light displays that resemble fireworks, and 3D TV.
The Pentagon is developing similar technology as a defensive device for military vehicles. Called the Plasma Acoustic Shield System (PASS), it creates violent effects by using an additional laser pulse to explode the initial plasma ball, producing a bright flash and a loud bang. It has recently been installed and successfully tested in a military vehicle.
A curtain of flash-bangs could be created instantly up to 100 metres away to provide a visual screen against snipers, says Keith Braun of the US army's Weapon Systems and Technology Directorate. Stellar Photonics of Bellevue, Washington, which developed PASS, plans to increase the number of laser pulses per second, says Braun, "to create a wall of light and sound".
By David Hambling, NewScientist
