Holography uses lasers to record and store light interference patterns to reproduce a 3D image of an object. It was invented in 1948 but required lasers, which were invented later, to become practical. A laser splits light into reference and object beams which are used to record the interference pattern on film, allowing 3D reconstruction of the object from different angles when viewed with laser light. Holograms have applications in authentication, museum displays, and optical data storage due to their high resolution 3D encoding of information.

1. HOLOGRAPHY
BY
K.N.M RAGHUVEER

2. CONTENTS
INTRODUCTION
HISTORY
WHY LASER?
CONSTRUCTION
WORKING
RECONSTRUCTION
APPLICATIONS
ADVANTAGES AND DISADVANTAGES
CONCLUSION

3. INTRODUCTION
 Holography (from the Greek)
is the science of producing holograms.
 It is an advanced form of photography that
allows an image to be recorded in three
dimensions.
The image changes as the position and
orientation of the viewing system changes in
exactly the same way as if the object were still
present, thus making the image appear
three-dimensional.

4. HISTORY
 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.

5. WHY LASER?
 Lasers produce
monochromatic
light -- it has one
wavelength and
one color.
 Because of the need
for coherent
interference
between the
reference and
object beams.

6. CONSTRUCTION
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.

7. 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.

9. APPLICATIONS
It is used for producing a three dimensional
image.
Authentication.
1. Identity card.
2. Passport.
3. Sticker or Tag.

10.  This is used for museum display.

11. ADVANTAGES
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.

12. DISADVANTAGES
 Hard to see without good direct point
source of light.
 Not that bright.
 It is expensive.
 Require complicated precise machinery to
produce and view an image

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

14. REFERENCES
 http://en.wikipedia.org/wiki/Holography
 http://spie.org/Documents/Publications/
00%20STEP%20Module%2010.pdf
 http://physics.ucsd.edu/neurophysics/courses
/physics_173_273/holography_02.pdf
 http://web.physics.ucsb.edu/~phys128/
experiments/holography/HolographyFall06.pdf

15. THANKYOU