Presented by: Manjukiran V

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What is Holography History Conventional vs. Holographic photography Properties Construction Working Reconstruction Use of Laser Applications Advantages and Disadvantages Conclusion

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Holography (from the Greek, whole + write) is the science of producing holograms

It is an advanced form of photography that allows an image to be recorded in three dimensions.

The technique of holography can also be used to optically store, retrieve, and process information.

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Invented in 1948 by Dennis Gabor for use in electron microscopy, before the invention of the laser

Leith and Upatnieks (1962) applied laser light to holography.

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Conventional: 2-d version of a 3-d scene Photograph lacks depth perception Film sensitive only to radiant energy Phase relation (i.e. interference) are lost

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Hologram: Freezes the intricate wavefront of light that

carries all the visual information of the scene To view a hologram, the wavefront is

reconstructed View what we would have seen if present at the

original scene through the window defined by the hologram

Provides depth perception

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If you look at these holograms from different angles, you see objects from different perspectives, just like you would if you were looking at a real object

They usually just look like sparkly pictures or smears of color

If you cut one in half, each half contains whole views of the entire holographic image.

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Laser : Red lasers, usually helium-neon (HeNe) lasers, are common in holography

Beam splitter: This is a device that uses mirrors and prisms to split one beam of light into two beams.

Mirrors: These direct the beams of light to the correct locations.

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Holographic film: Holographic film can record light at a very high resolution, which is necessary for creating a hologram. It's a layer of light-sensitive compounds on a transparent surface, like photographic film.

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Lasers produce monochromatic light -- it has one wavelength and one color.

Because of the need for coherent interference between the reference and object beams

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Authentication.

Virtual Display.

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Identity card.Passport.Sticker or Tag.

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Hologram stickers cannot be scanned or photocopied .

Hologram stickers can also create a unique and attractive complement to your existing packaging and product.

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Sci-fic movies.

For trade-show booths.

Museums display .

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Holography is a high resolution three dimensional recording of an object from a limited perspective.

Security: Holograms are widely used for security purpose.

It is not possible to duplicate Holograms Holograms are quick and easy optical validation.

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Hard to see without good direct point source of light.

Not that bright. Not visible in dark.

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Holographic images provides viewer a 3-dimensional view of an object and they are effective in authentication purpose.

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Hologram Scaling with Wavelength http://hyperphysics.phy-astr.gsu.edu/Hbase/optmod/scaleh.html#c1

N. J. Phillips and D. Porter, "An advance in the processing of holograms," Journal of Physics E: Scientific Instruments (1976) p. 631

Specular holography http://www.zintaglio.com/how.html

Scaling Holographic Images, http://hyperphysics.phy-astr.gsu.edu/Hbase/optmod/holog.html#c5

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