Holograms

A hologram is a three-dimensional image that can be seen without special equipment. Holograms are created by splitting a laser beam into two beams that interfere to form a pattern on a sensitive surface. The brain then interprets the pattern as a three-dimensional image.

Holography dates back to 1947, when scientist Dennis Gabor first developed the theory. Gabor coined the term hologram from the Greek words holos, meaning “whole,” and gramma, meaning “message”. A hologram image employs monocular depth cues, including parallax and stereopsis; however, it does not (normally) employ object movement (fully), reflection (fully), and also does not employ occlusion (correctly with respect to the integrity of the holographic image and also real-world context).

We can conclude that, whilst to some extent realistic, a hologram image is not truly realistic (or perfectly matched) 3-D imagery!

Principles

  • A laser beam is split into two; one beam images an object while the other hits a photographic plate, recording the interference pattern from the reflected light.

Applications

  • Product displaysHolograms can be used to showcase products in a visually appealing way.
  • Technical concepts: Holograms can be used to present complex technical concepts.
  • Medical imagingHolograms can be used to create detailed images of the inside of live organs.
  • Security: Holograms can be used on ID cards and credit cards to prevent copying.
  • Other usesData storage, microscopy, and interferometry.