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The hologram keeps the information on the amplitude and phase of the field. Several holograms may keep information about the same distribution of light, emitted to various directions. The numerical analysis of such holograms allows one to emulate large numerical aperture, which, in turn, enables enhancement of the resolution of optical microscopy.
The holograms found on credit cards are examples of rainbow holograms. These are technically transmission holograms mounted onto a reflective surface like a metalized polyethylene terephthalate substrate commonly known as PET.
The prime example of holography is the AdS/CFT correspondence. The holographic principle was inspired by the Bekenstein bound of black hole thermodynamics , which conjectures that the maximum entropy in any region scales with the radius squared , rather than cubed as might be expected.
The rainbow hologram (also known as Benton hologram) is a type of hologram that was invented in 1968 by Dr. Stephen A. Benton at Polaroid Corporation (later MIT). [1] Rainbow holograms are designed to be viewed under white light illumination, rather than laser light which was required before this.
A holographic display is a type of 3D display that utilizes light diffraction to display a three-dimensional image to the viewer. Holographic displays are distinguished from other forms of 3D displays in that they do not require the viewer to wear any special glasses or use external equipment to be able to see the image, and do not cause a vergence-accommodation conflict.
Ordinary holograms are three-dimensional images encoded in a two-dimensional surface, such as the hologram on a typical credit card. "This time, the entire universe is encoded," he said.
Volume holograms are holograms where the thickness of the recording material is much larger than the light wavelength used for recording. In this case diffraction of light from the hologram is possible only as Bragg diffraction, i.e., the light has to have the right wavelength (color) and the wave must have the right shape (beam direction, wavefront profile).
Computer-generated holography (CGH) is a technique that uses computer algorithms to generate holograms.It involves generating holographic interference patterns.A computer-generated hologram can be displayed on a dynamic holographic display, or it can be printed onto a mask or film using lithography. [1]