Holographic memory uses interference patterns of laser light to store massive amounts of data in three-dimensional crystals or photopolymers. Holographic Versatile Discs (HVDs) can store up to 3.9 terabytes in a sugar cube-sized crystal using two lasers - a green laser for writing and reading, and a red laser for positioning. Data is written by splitting a laser into reference and object beams that intersect in the recording material, and read by illuminating the material with the original reference beam. Holographic memory offers high data density and transfer rates but faces challenges in engineering complex optical components and developing highly sensitive recording materials.

1. HOLOGRAPHIC
HOLOGRAPHIC
MEMORY
MEMORY

2.  Contents
 1. Introduction.
 2. What is Holographic memory?
 3. What is HVD?
 4. Structure of HVD.
 5. How HVD Works?
 I. Writing Data
 II. Reading Data
 6. Advantages of HVD
 7. Limitations AND Challenges
 8. How HVD compares with other
 storage device?
 9. Conclusion

3. Introduction
 A hologram is a 3D image reproduced form a
pattern of interference.
 The Holography technique was invented in
1948 by the Hungarian Dennis Gabor.
 It can store up to 1-4 TB of information in a
sugar cube sized crystal.
 It promises to be the data storing system of
the future. Hence holographic storage system
has the potential to became the next storage
generation over conventional storage system.

4. What is Holographic Memory?
 Holographic memory is a three-dimensional
data storage system that can store
information at high density inside the crystal or
photopolymer.
 It is a memory that can store information in
the form of holographic image (hologram)
 Like other media, holographic media is
divided into write once (where the storage
medium undergoes some irreversible
change), and rewritable media (where the
change is reversible).

5. Holographic
Versatile Disc
 These discs have the
capacity to hold up to 3.9
terabyte (TB) of
information, which is
approximately 6,000 times
the capacity of a CD-
ROM, 830 times the capacity
of a DVD, 160 times the
capacity of single-layer Blu-
ray-Discs, and about 8 times
the capacity of standard
computer hard drives as of
2007.
 The HVD also has a transfer
rate of
1gigabyte/s

6. COMPONENTS
 Most holographic storage systems contain some
components basic to the setup.
 These are:-
 a) Laser Beam
 b) Beam Splitters to split the Laser Beam
 c) Mirrors to direct the Laser Beam
 d) A liquid crystal Display panel (SLM)
 e) Lenses to focus the Laser Beam
 f) Recording Material
 g) CCD cameras

7. Holographic Versatile Disc
structure 1. Green writing/reading
laser (532 nm)
2. Red
positioning/addressing
laser (650 nm)
3. Hologram (data)
4. Polycarbonate layer
5. Photo polymeric layer
(data- containing layer)
6. Distance layers
7. Dichroic layer (reflecting
green light)
8. Aluminum reflective
layer
(reflecting red light)
9. Transparent base

8. How it Works
 Laser beams splits into 2 beams.
o Beams works as object beam and Reference
beam.
 To read the stored data, the media is
illuminated by original reference beam.
 Thousands of Holograms can be stored in the
same location by simply changing angle of
reference.
 Multiple Data Recording is possible by Using
Light at Different angles

10. Holographic Technology at
Glance
 Advantages
 Associative memory capability
 Access All the Data in Few Microseconds
 Storage Capacity Increased Multiple
Folds
 The HVD also has a transfer rate of 1
gigabit/s.

11. Picture of the above
explanation

12. LIMITATIONS AND CHALLENGES
 It is very difficult to arrange all of those
components like CCD camera , SLM
arrays and beam steering devices.
 Needs good recordings sensitive material
to allow high data transfer rate.
 If too many pages are stored in one
crystal, the strength of each hologram
gets diminished.

13. Advantages
A) Pet flop
Computing
B) Data Mining
C) Future
Computing
System

14. CONCLUSION
But even then the
holographic way of
storing data is still at
However this
the base stage and
technology itself is
It may offer high it may take another
dazzling and aims to
data transfer rate. couple of years for
light up the desktop
this technique to hit
Experiences.
desktop with a real
life data storage
solution.

15. Thank you