25-08-2017, 09:32 PM
HOLOGRAM SYSTEM
1HOLOGRAM.pptx (Size: 1.05 MB / Downloads: 30)
History Of Hologram
Theory Developed in 1947 by British/Hungarian scientist Dennis Gabor.
Development in this field was difficult during the 1950’s because light sources were not coherent. Invention of laser overcame the non-coherent light problem.
In 1962 Emmett Leith and Juris Upatnieks realized that holography could be used as a 3-D visual medium.
From their work, they used a laser to create the first hologram in history, that of a toy,train and bird.
What is Holograms ?
A hologram is a recording of an object by the method of holography by using light waves.
Holography works upon the physical properties of light that creates the magic.
The use of holography is not only to record images but it is getting used to store optical information
Two of the most commonly used data storage places in media are CD and DVD.
Holograms can be made from photos, flat art which is designed by Corel Draw, Illustrator, Photoshop or other software.
Recording Of Hologram
Holography is in principle an interference based technique.
Laser beam is divided into two parts.
Second beam illuminates the object & the diffracted or scattered beam falls on the photographic plate.
First beam (reference beam) reflected on photographic plate mirror.
Film exposed simultaneously to reference beam and scattered beam.
Both beam belong to same laser wave fronts, the beam interference on the plate.
Obtain complicated interference pattern on the film.
Film called hologram.
Hologram contain information not only about amplitude but also phase of the object.