by shamini, student at stanley college of engineering and technology, hyderabad

1. HOLOGRAHIC VERSATILE DISK
GUIDED BY:
MRS. V. SUDHARSHANI
PRESENTED BY:
K. SHAMINI

2. CONTENTS:
• Introduction
• Need of HVD
• What is HVD?
• Basics of holographic memory
• Technology used in HVD
• Structure of HVD?
• Writing data
• Reading data
• Advantages, disadvantages and applications of
HVD
• Facts
• Future aspects
• conclusion

3. INTRODUCTION
• HVD is an advanced optical disk that’s presently
in the development stage.
• Storage capacity: 1 terabyte (Tb)
• Data transfer rate: 1 gigabit per second
• The technology permits over 1 kilobits of data to
be written and read in parallel with a single flash.

4. Need for HVD?

6. Types of optical
storage
Capacity
Writing/
Reading
Speed
Discs
Approx.
Cost
Recordable
Player
Approx.
Cost
Holographic
Versatile
Discs
(HDSS)
HVD
300 GB–
1.6 TB
1 GB/s $120 $3000
Blu-ray
Discs
BD
25 GB–
50 GB
36.5
Mb/s
$18 $2000
Digital
Versatile
Discs
DVD–
HD-
5 GB–
30 GB
36.5
Mb/s
$10 $2000
Compact
Discs
CD
783 MB–
1.3 GB
36.5
Mb/s
$4 $200

7. What is HVD?
• Holographic versatile disk is a holographic storage
format that looks like a DVD but is capable of storing
far more data.
• Prototype HVD devices have been created with a
capacity of 3.9TB and a transfer rate of 1GBPS.
• 1HVD=5,500 CD’s=830 DVD’s=160 Blu-ray discs.
• Uses laser beams to store data in 3D.

8. Basics of holographic memory
• Holography is a method of recording patterns of light to
produce a 3D object .
• Recorded patterns of light is called a hologram.
• Creation of a hologram begins with a focused beam of light,
a laser.
• Laser splits up into two beams:
1. Reference beam
2. Information beam
• When light encounters an image its composition changes.

9. • When the information beam encounters an image, it
carries that image in its waveforms
•When the two beams intersect, it creates a pattern of
light interference and that can be recorded on the
photosensitive polymer layer of the disk.
• To retrieve the information stored in a hologram,
shine the reference beam onto the hologram. When it
reflects off the hologram, it holds the image pattern of
the stored image.
• This reconstruction beam is then sent to a CMOS
sensor to recreate the original image.

10. Technology used in HVD
• Collinear holography- the laser beams are collimated.
• Blue-green laser reads the data encoded in the form of
laser interference.
• Red laser serves the purpose of reference beam and to
read servo info.
• A layer of dichroic mirrors, between the holographic
and servo data layer reflects the blue-green laser
beam, letting only the red laser to pass through it to
reach the servo information .

11. • The concepts of collinear holographic memories
are:
• To increase the recording capacity, thick volume-recording
media is used.
• Optical disk is pre-formatted with addresses and
optical servo information.
• The beam for the optical servo is utilized to
provide backward compatibility with d existing CD’s
and DVD’s.

13. Structure of HVD
The holographic versatile disk structure consists of the
following components:
• Green writing/reading laser (532nm)
• Red position/addressing laser (650nm)
• Hologram (data)
• Polycarbon layer
• Photo polymeric layer (data-containing layer)
• Distance layers

14. • Dichroic layer (reflecting green light)
• Aluminum reflective layer (reflecting
red light)
• Transparent base

15. Writing Data
• a simplified HVD system consists of the following main
components:
• Blue or green laser (532nm wavelength)
• Beam splitter/merger
• Mirrors
• Spatial light module (SLM)
• CMOS sensor
• Photopolymer recording medium

16. Information is encoded into binary and is stored in the
SLM.
These data are turned into ones and zeros represented as
opaque or translucent areas on a ‘page’.
When the information beam passes through the SLM,
portions of the light are blocked by the opaque areas of the
page, and portions pass through the translucent areas.
When the reference beam and the information beam rejoin
on the same axis, they create a pattern of light interference,
the holography data.
This interference pattern is stored in the photopolymer area
of the disc as a hologram.

18. Reading Data:
• To read, we have to retrieve the light pattern stored in the
hologram
• Laser is projected onto the hologram –a light beam that is
identical to the reference beam.
• The hologram diffracts this beam according to the specific
pattern of light interference is storing.
• The resulting light recreates the image of the page that
established the light-interference pattern-reconstruction
beam.

19. •The CMOS sensor then reproduces the page data.
•The reconstruction beam-bounces back off the disc, it travels to the
CMOS sensor.

20. Advantages, Disadvantages And Applications
• Advantages:
• More storage capacity
• Data transfer date is high
• Disadvantages:
• Initial price of the player and disk are high
• Price and data storage not confirmed still in R & D
• Applications:
• Used for storing large amounts of data most likely for large
companies
• Could be the most efficient way to back up information in the
near future.

21. Facts
• The entire US library of congress can be stored on six
HVD’s, assuming that every book has been scanned in
the text format. The library of congress is the largest
in the world and contains over 130 million items.
• The pictures of every landmass of earth-like the one
shown in the Google earth can be stored on two
HVD’s.

22. Future Aspects
• Have tremendous implications in the commercial,
industrial and d-cinema realms.
• Will find wide use for backing up and archiving the
media libraries, including the one at the Hollywood
studios.

23. Conclusion
• The HDV’s will soon replace DVDs and blu-ray
disks.
• Currently supported by more than 170 of the
worlds leading consumer electronics, personal
computer, recording media, video game and music
company.
• The format has also broad support from the major
movie studios as a successor to today's DVD and
blu-ray disk format.