If a beam similar to the original reference beam is shone through a hologram, the result is a three-dimensional image of the object scanned.

ECONOMIST: Researchers can now broadcast moving holograms

When the reflected object beam and the reference beam are recombined, they create an interference pattern that encodes the 3-D image.

ENGADGET: Infrared holography lets rescuers see people through walls, fire, walls of fire (video)