Holography

Summary

Holography records a light wave with its phase, not only its intensity, and later rebuilds the same wave. The object wave is made to interfere with a known reference wave, and the recording medium stores the resulting fringe pattern. Lit again by the reference wave, the recorded pattern diffracts light into a copy of the original object wave. Dennis Gabor introduced the method, and it gives three-dimensional images as well as tools for measurement and data storage.