the American radar researchers Emmett Leith and Juris Upatnieks of the University of Michigan, USA, produced a Hologram in 1962, building on theoretical work by British/Hungarian physicist Dennis Gabor, done in 1948.
Dennis Gabor had been unable to produce an actual hologram, because a suitable coherent light source had not yet been invented. Leith and Upatnieks used Gabor’s ideas on light interferometry with their research to produce a side-looking radar. By using a laser (invented two years earlier) and off-axis split-beam techniques from the radar research, the two Americans created the first true three-dimensional flat image. The hologram image of a toy train and bird could only be seen when it was illuminated by a laser beam.
Also in 1962, the first hologram viewable with the light from a light bulb was invented by Soviet physicist Uri N. Denisyuk in Leningrad (now St. Pe-tersburg, Russia). His white-light reflection hologram, the first hologram that did not need to be illuminated by a laser in order to be seen.
Gabor coined the term “hologram” from the Greek words holos (“whole”) and gramma (“message”).
- What is Holography? | holocenter
A hologram is a physical structure that diffracts light into an image. The term ‘hologram’ can refer to both the encoded material and the resulting image. A holographic image can be seen by looking into an illuminated holographic print or by shining a laser through a hologram and projecting the image onto a screen.
- Holography – Wikipedia
Holography is the science and practice of making holograms. Typically, a hologram is a photographic recording of a light field, rather than of an image formed by a lens, and it is used to display a fully three-dimensional image of the holographed subject, which is seen without the aid of special glasses or other intermediate optics.
- How Holograms Work | HowStuffWorks
f you want to see a hologram, you don’t have to look much farther than your wallet. There are holograms on most driver’s licenses, ID cards and credit cards.
- Holograms Aren’t The Stuff of Science Fiction Anymore – Singularity Hub
Holograms appear to be all around us now. Long-dead rapper Tupac Shakur showed up at the 2012 edition of the Coachella music festival. Microsoft’s HoloLens seems akin to a wearables version of Star Trek’s holodeck, allowing its user to interact with 3D objects in an augmented reality.
- How holograms work – Explain that Stuff
How many holograms have you got in your pocket? If you’re carrying any money, the answer is probably “quite a few.”