Holography - state of the art

Screens with the ability to display three-dimensional images are already quite common. Real holography, with volumetric displays, which enable the observer to go around the displayed subject and look at it from all sides, exist so far only in experimental research set-ups.

To generate a stereo image pair you just need a simple sheet of paper with two images - one for each eye - our brain creates the spatial overall impression. Today it is mostly the illusion of a 3D image, generated with the help of projectors, mirrors and transparent displays. So we believe that holography is already easily achievable. Apparently holographic images, as in the Heliodisplay (as reported in November 2007), are only an illusion of depth appeal.

The crucial for a real holographic image is that in a three-dimensional space all "space pixel" have to be part of the display. The display may not be a plate, but a volumetric body. Different approaches try to solve this task.

The rotating mirror

A rotating mirror, which rotates so fast that it seems to be invisible, is one approach to get a volumetric display. Coupled with a high-speed projector and the right software a moving hologram can be produced.

Research set-up at the University of Southern California (youtube video)

Holodust - the 3D dust-display
In another approach researchers try to produce the hologram in a artificially generated dust cloud. The exact position of each dust particle is identified by using an infrared laser. If a dust particle gets randomly in the correct position, a second laser gets it to shine. Is the distribution of the dust particles well enough a static or moving 3D image can be generated.

The Holodust concept from New York University (video)