hologram

[hol-uh-gram, hoh-luh-]

noun

Optics.

1. a negative produced by exposing a high-resolution photographic plate, without camera or lens, near a subject illuminated by monochromatic, coherent radiation, as from a laser: when it is placed in a beam of coherent light a true three-dimensional image of the subject is formed.

hologram

/ ˈhɒləˌɡræm /

noun

1. a photographic record produced by illuminating the object with coherent light (as from a laser) and, without using lenses, exposing a film to light reflected from this object and to a direct beam of coherent light. When interference patterns on the film are illuminated by the coherent light a three-dimensional image is produced

hologram

1. A three-dimensional image of an object made by holography.

Word History and Origins

Origin of hologram¹

First recorded in 1945–50; holo- + -gram ¹

A Closer Look

To produce a simple hologram, a beam of coherent, monochromatic light, such as that produced by a laser, is split into two beams. One part, the object or illumination beam, is directed onto the object and reflected onto a high-resolution photographic plate. The other part, the reference beam, is beamed directly onto the photographic plate. The interference pattern of the two light beams is recorded on the plate. When the developed hologram is illuminated from behind (in the same direction as the original reference beam) by a beam of coherent light, it projects a three-dimensional image of the original object in space, shifting in perspective when viewed from different angles. Appropriately enough, the word hologram comes from the Greek words holos, “whole,” and gramma, “message.” If a hologram is cut into pieces, each piece projects the entire image, but as if viewed from a smaller subset of angles. The large amount of information contained in holograms makes them harder to forge than two-dimensional images. Many credit cards, CDs, sports memorabilia, and other items include holographic stickers as indicators of authenticity. Holography is used in many fields, including medicine, data storage, architecture, engineering, and the arts.

Example Sentences

A hologram of neon greens, reds, and yellows explodes from the puck, making my eyes ache.

Read more on Literature

“And they let you blend the physical and digital worlds together with holograms.”

Read more on Los Angeles Times

Clips showed fridges lined with blue boxes featuring holograms and "Molecule Plus" labels.

Read more on BBC

The hologram, at least the one on the show floor, is not really a hologram.

Read more on Los Angeles Times

Other objects included a pocket TV, a snowflake hologram and a photo of Princess Diana.

Read more on BBC