n.
Method of recording or reproducing a three-dimensional image, or hologram, by means of a pattern of interference produced using a laser beam.
To create a hologram, a beam of coherent light (a laser) is split; half the beam falls on a recording medium (such as a photographic plate) unaltered, and the other half is first reflected off the object to be imaged. The two beams together produce an interference pattern of stripes and whorls on the plate. The developed plate is the hologram. When light is shone on the hologram, a three-dimensional image of the original object is produced by the recorded interference pattern. Some holograms require laser light to reproduce the image; others may be viewed in ordinary white light. Holography was invented in 1947 by the Hungarian-British physicist Dennis Gabor (19001979), who won a 1971 Nobel Prize for his invention.