It is the first updatable 3D display with memory ever to be developed -- and can be viewed without special eyewear.

"This is a new type of device, nothing like the tiny hologram of a dove on your credit card," said Nasser Peyghambarian, co-developer and professor of optical sciences at the University of Arizona.

"The hologram on your credit card is printed permanently. You cannot erase the image and replace it with an entirely new three-dimensional picture."

Peyghambarian believes that the technology will eventually make its way into everyday life.

"Imagine that when you walk into the supermarket or department store, you could see a large, dynamic, three-dimensional product display."

The scientists believe that their work could finally make holograms feasible for practical applications.

"Holography has been around for decades, but holographic displays are really one of the first practical applications of the technique," said Savas Tay, co-developer and optical science researcher at the University of Arizona.

The prototype measures four inches square and only projects in red, but the researchers see larger full-colour displays as realistic in the near future.

"We use highly efficient, low-cost recording materials capable of very large sizes, which is very important for life-size, realistic 3D displays," Peyghambarian said.

"We can record complete scenes or objects within three minutes and can store them for three hours."

The researchers are now experimenting with pulsed lasers as a way to improve image quality.

"If you can write faster with a pulsed laser, then you can write larger holograms in the same amount of time it now takes to write smaller ones," Tay said.

"We envision this to be a life-size hologram. We could, for example, display an image of a whole human that would be the same size as the actual person."

Tay sees that holograms could one day soon become a vital diagnostic tool for doctors.

"Three-dimensional imaging techniques are already commonly used in medicine, for example, in MRI or CAT scan techniques," said Tay.

"However, the huge amount of data that is created in three dimensions is still being displayed on two-dimensional devices, either on a computer screen or on a piece of paper."

"A great amount of data is lost by displaying it this way."

"So I think when we develop larger, full-color 3D holograms, every hospital in the world will want one."