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Dennis Gabor devised holography as a way to record and reconstruct a wavefront. Recording the wave interference between an object field and a known reference field preserves information about relative wave phase in an intensity pattern. Illuminating that pattern with the reference field can reconstruct an image-bearing field. His early motivation was improved electron microscopy; his Nobel lecture explains how later laser sources and tilted-reference arrangements overcame practical limitations of the original in-line geometry.^[ref]

A physicist.^[ref]

Emmett Leith was an electrical engineer whose work with Juris Upatnieks developed wavefront reconstruction through a communication-theory treatment of holography. Their 1962 paper analyzed recording and reconstruction as a sequence of modulation, propagation and intensity detection, and tested methods for improving the reconstructed signal.^[ref]

The connection is useful because an intensity recording can contain information about an optical wave's phase through interference with a reference wave. Changing the recording geometry can separate the desired reconstruction from unwanted terms. Their work helped make clear three-dimensional holographic images practical while linking optical processing with spatial frequency analysis.^[ref]

Holography records the wave interference between a holographic object wave and a known holographic reference wave, then uses that record to reconstruct a wavefront. The record is a hologram. A photographic plate or photodetector measures light intensity; the relative wave phase is encoded in the positions and contrast of interference fringes, rather than measured directly as an optical oscillation. Reillumination makes the recorded pattern act as a diffraction grating that produces an image-bearing field.

The useful change of viewpoint is to preserve a field that can propagate again, instead of only a focused brightness picture. Recovered complex amplitude permits refocusing with the Fresnel propagator; a spatially extended hologram can also supply different viewing directions. The recoverable information is limited by the collected aperture, recorded spatial frequencies, optical coherence and separation of unwanted diffraction orders.

Juris Upatnieks and Emmett Leith developed laser holography, publicly demonstrating a three-dimensional hologram in 1964. A tilted reference light field records wave interference with the field scattered by an object. During reconstruction, its angle helps separate the desired image from the other reconstructed components. The long coherence length of a laser made this geometry practical, allowing the reference path to go around the object.^[ref][ref]

A physicist.^[ref][ref]

Awarded to Dennis Gabor for inventing and developing holography.^[ref]