08 November 2010

Moving Holograms

A team led by optical sciences developed a new type of holographic telepresence that allows the projection of a three-dimensional, moving image without the need for special eyewear such as 3D glasses or other auxiliary devices. The technology is likely to take applications ranging from telemedicine, advertising, updatable 3D maps and entertainment to a new level. Holographic telepresence means we can record a three-dimensional image in one location and show it in another location, in real-time, anywhere in the world. The prototype device uses a 10-inch screen, but researchers are already successfully testing a much larger version with a 17-inch screen. The image is recorded using an array of regular cameras, each of which views the object from a different perspective. The more cameras that are used, the more refined the final holographic presentation will appear.

That information is then encoded onto a fast-pulsed laser beam, which interferes with another beam that serves as a reference. The resulting interference pattern is written into the photorefractive polymer, creating and storing the image. Each laser pulse records an individual hogel (or holographic pixel) in the polymer. A hogel is the three-dimensional version of a pixel, the basic units that make up the picture. The hologram fades away by natural dark decay after a couple of minutes or seconds depending on experimental parameters. Or it can be erased by recording a new 3D image, creating a new diffraction structure and deleting the old pattern. The overall recording setup is insensitive to vibration because of the short pulse duration and therefore suited for industrial environment applications without any special need for vibration, noise or temperature control. Potential applications of holographic telepresence include advertising, updatable 3D maps, telemedicine and entertainment.

More information:

http://uanews.org/node/35220