Holography is a technique that uses lasers and interference to record light fields and recreate three-dimensional images without the original objects present. It involves recording the interference pattern of a light source and light scattered off objects. When illuminated with the original light source, the hologram reconstructs the light field and original scene appears three-dimensional. Current applications include holographic interferometry, security holograms, and heads-up displays. Future uses may include holographic memory, optical computing, and architectural modeling and sales.

1. Holography

2. What is Holography?
 Holography is a technique which enables three-
dimensional images to be made.
 It involves the use of a laser, interference, diffraction,
light intensity recording and suitable illumination of the
recording.
 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.

3. Holography or ‘Lens less photography’
 Holography is a technique that enables a light field, which is generally the product of
a light source scattered off objects, to be recorded and later reconstructed when the
original light field is no longer present, due to the absence of the original objects.
 There are two physical phenomena as the principles of the holography: interference
and diffraction of light waves.
 When the two laser beams reach the recording medium, their light waves intersect
and interfere with each other. It is this interference pattern that is imprinted on the
recording medium. The pattern itself is seemingly random, as it represents the way in
which the scene's light interfered with the original light source — but not the original
light source itself. The interference pattern can be considered an encoded version of
the scene, requiring a particular key — the original light source — in order to view its
contents.

4. Theory

5. Planar view of interference pattern

6. Physical Model

7. Formation of Hologram

8. Virtual Image

9. Real image

10. Holography –
Current and
Future
Applications

11. Current Applications
 Holographic interferometry is used by researchers and industry designers to
test and design many things, from tires and engines to prosthetic limbs and
artificial bones and joints.
 Supermarket and department store scanners use a holographic lens system
that directs laser light onto the bar codes of the merchandise.
 Holographic optical elements (HOE’s) are used for navigation by airplane
pilots. A holographic image of the cockpit instruments appears to float in
front of the windshield. This allows the pilot to keep his eyes on the runway
or the sky while reading the instruments. This feature is available on some
models of automobiles.

12.  Holograms are used in advertisements
and consumer packaging of products to
attract potential buyers.
 The use of holograms on credit cards and
debit cards provide added security to
minimize counterfeiting..
 Sony Electronics uses holographic
technology in their digital cameras. A
holographic crystal is used to allow the
camera to detect the edge of the subject
and differentiate between it and the
background. As a result, the camera is
able to focus accurately in dark
conditions.

13. Future Application
 Future colour liquid crystal displays (LCD’s) will be brighter and
whiter as a result of holographic technology. Scientists at Polaroid
Corp. have developed a holographic reflector that will reflect ambient
light to produce a whiter background.
 Holographic night vision goggles.
 Holographic memory is a new optical storage method that can store 1
terabyte (= 1000 GB) of data in a crystal approximately the size of a
sugar cube. In comparison, current methods of storage include CD’s
that hold 650 to 700 MB, DVD’s that store 4.7 GB, and computer hard
drives that hold up to 120 GB.
 Optical computers will be capable of delivering trillions of bits of
information faster than the latest computers.

14. Future of holography
 Holography is a very useful
tool in architecture.
 Use of holography in
architecture is recording of
models and previsualise
new buildings.
 It can provide attractive
method to traditional
methods in sales and
presentation.

15.  Advanced
laser, optics, image
processing are incorporated
into Zebra 3D imaging to
produce Holography images.
 This holography is possible to
create large city maps, full
seized cars, humans, and
machines