1. ABSTRACT
The first step in understanding holographic memory is to understand what "holographic" means.
Holography is a method of recording patterns of light to produce a three-dimensional object. The
recorded patterns of light are called a hologram.
The process of creating a hologram begins with a focused beam of light -- a laser beam. This
laser beam is split into two separate beams: a reference beam, which remains unchanged
throughout much of the process, and an information beam, which passes through an image.
When light encounters an image, its composition changes. In a sense, once the information beam
encounters an image, it carries that image in its waveforms. When these two beams intersect, it
creates a pattern of light interference. If you record this pattern of light interference -- for
example, in a photosensitive polymer layer of a disc -- you are essentially recording the light
pattern of the image.
To retrieve the information stored in a hologram, you shine the reference beam directly onto the
hologram. When it reflects off the hologram, it holds the light pattern of the image stored there.
You then send this reconstruction beam to a CMOS sensor to recreate the original image.
Most of us think of holograms as storing the image of an object, like the Death Star pictured
above. The holographic memory systems we're discussing here use holograms to store digital
instead of analog information, but it's the same concept. Instead of the information beam
encountering a pattern of light that represents the Death Star, it encounters a pattern of light and
dark areas that represent ones and zeroes.
HVD offers several advantages over traditional storage technology. HVDs can ultimately store
more than 1 terabyte (TB) of information -- that's 200 times more than a single-sided DVD and
20 times more than a current double-sided Blu-ray. This is partly due to HVDs storing holograms
in overlapping patterns, while a DVD basically stores bits of information side-by-side. HVDs
also use a thicker recording layer than DVDs -- an HVD stores information in almost the entire
volume of the disc, instead of just a single, thin layer.
Holographic memory systems have been around for decades. They offer far more storage
capacity than CDs and DVDs -- even "next-generation" DVDs like Blu-ray -- and their transfer
rates leave conventional discs in the dust. So why haven't we all been using holographic memory
for years now?There are several hurdles that have been holding holographic storage back from
the realm of mass consumption, including price and complexity. Until now, the systems have
required a cost-prohibitive level of precision in manufacturing. But recent changes have made
the holographic versatile disc (HVD) developed by Optware a viable option for consumers.
HVD also includes servo data. The servo beam in the HVD system is at a wavelength that does
not photosensitize the polymer recording medium. In the HVD test system, the servo data is
carried in a red (650-nm wavelength) laser. The size and thickness of an HVD is also compatible
with CDs and DVDs.
[1]

2. INTRODUCTION
Holographic memory has been around for more than 40 years, but several characteristics made it
difficult to implement in a consumer market. First off, most of these systems send the reference
beam and the information beam into the recording medium on different axes. This requires
highly complex optical systems to line them up at the exact point at which they need to intersect.
Another drawback has to do with incompatibility with current storage media: Traditionally,
holographic storage systems contained no servo data, because the beam carrying it could
interfere with the holography process. Also, previous holographic memory discs have been
notably thicker than CDs and DVDs.
Optware has implemented some changes in its HVD that could make it a better fit for the
recording medium at the same angle, which Optware calls the collinear method. According to
Optware, this method requires a less complex system of optics, enabling a smaller optical pickup
that is more suited to consumer use. The process of creating a hologram begins with a focused
beam of light -- a laser beam. This laser beam is split into two separate beams: a reference beam,
which remains unchanged throughout much of the process, and an information beam, which
passes through an image. When light encounters an image, its composition changes (see How
Light Works to learn about this process). In a sense, once the information beam encounters an
image, it carries that image in its waveforms. When these two beams intersect, it creates a pattern
of light interference. If you record this pattern of light interference -- for example, in a
photosensitive polymer layer of a disc -- you are essentially recording the light pattern of the
image. The HVD process uses a blue-green laser beam, used for reading and writing data,
collimated (made parallel) with a red laser beam, which is used for servo and tracking.
In the recording process, the initial laser is split into two beams. One of the beams passes
through a device called a spatial light modulator (SLM) and combines with the direct beam to
produce a hologram in the physical medium. To recover the data, another 532-nm laser is
directed into the hologram, which diffracts the laser beam. The resulting image constitutes an
optical reproduction of the original recorded data. A photosensitive semiconductor device
converts this optical data into the original digital files.
The first working HVD systems for the enterprise are expected to be shipped in 2006, with
consumer HVDs and drives to become available in 2008 or later. The initial target market is
high-volume mass storage, such as digital television (DTV) broadcasts and document libraries in
large businesses and government agencies. Holography is the technique of recording the
scattered light off an object, and then displaying this recorded image so that it appears as if the
object is present is the same position as before, relative to the viewer. In other words, holography
represents a three-dimensional image of an object. Holograms are volumetric images of objects
within a two-dimensional medium.
Holographic memory has been around for more than 40 years, but several characteristics made it
difficult to implement in a consumer market. First off, most of these systems send the reference
beam and the information beam into the recording medium on different axes. This requires
highly complex optical systems to line them up at the exact point at which they need to intersect.
Another drawback has to do with incompatibility with current storage media: Traditionally,
holographic storage systems contained no servo data, because the beam carrying it could
interfere with the holography process. Also, previous holographic memory discs have been
[2]

3. notably thicker than CDs and DVDs. Optware has implemented some changes in its HVD that
could make it a better fit for the consumer market. In the HVD system, the laser beams travel in
the same axis and strike the recording medium at the same angle, which Optware calls the
collinear method. According to Optware, this method requires a less complex system of optics,
enabling a smaller optical pickup that is more suited to consumer use. The combination of high
storage densities, fast transfer rates, with durable, reliable, low cost media, make holography
poised to become a compelling choice for next-generation storage solution to the data archival
requirements of the commercial, medical, governmental and broadcast industries.Holographic
storage uses two laser beams, a reference and a data beam to create an interference pattern at a
medium where the two beams intersect. This intersection causes a stable physical or chemical
change which is stored in the medium. This is the write sequence. During reading, the action of
the reference beam and the stored interference pattern in the medium recreates this data beam
which may be sensed by a detector array. The medium may be a rotating disk containing a
polymeric material, or an optically sensitive single crystal.
InPhase Technologies announced that they would release the first commercially available
holographic drive in May 2008. InPhase's drive, the tapestry, costs $18,000 (USD). The first
version of the storage media, which cost $180, holds 300 gigabytes (GB) of data on a 5.25-inch-
wide, 3.5-millimeter-thick disk contained in a cartridge. The media is currently write once read
many (WORM). InPhase plans to create a re- writable version.
Features of the tapestry drive and media include:
An archive life of 50 years.
Does not require strict control of temperature and humidity levels.
Better data recovery: The holographic nature of the stored data page mean that the whole
can be recreated from a fragment.
20-120 megabytes per second (MBps) transfer rate.
Compatibility with existing small computer systems interface (SCSI), Fibre Channel (FC)
and Ethernet interfaces.
Potential future capacities up to 1.6 terabytes.
In late 1995 a joint university/industry/government consortium initiated the Holographic Data
Storage System (HDSS) programme, with the initial goals of developing several key components
for the system, including a high-capacity, high-bandwidth spatial light modulator used for data
input; optimised sensor arrays for data output; and a high-power red-light, semiconductor laser.
At the same time, the HDSS researchers were to explore issues relating to the optical systems
architecture (such as multiplexing schemes and access modes), data encoding/decoding methods,
signal processing techniques, and the requirements of target applications. Into the programme’s
final year, progress has been such that consortium member – IBM Research Division – believed
that holograms could hold the key to high-capacity data storage in the next millennium.
In holographic data storage, an entire page of information is stored at once as an optical
interference pattern within a thick, photosensitive optical material. Therein lie the reasons why
holographic data storage is able to both break through the density limits of conventional storage
and achieve data transfer rates significantly higher than current optical storage devices:
[3]

4. unlike other technologies that record one data bit at a time, holography allows a million
bits of data to be written and read in parallel with a single flash of light, and
it is by going beyond recording only on the surface, to recording through the full depth of
the medium that holographic data storage is able to break through the density limits of
conventional storage.
The combination of high storage densities, fast transfer rates, with durable, reliable, low cost
media, make holography poised to become a compelling choice for next-generation storage
solution to the data archival requirements of the commercial, medical, governmental and
broadcast industries.
Holographic storage uses two laser beams, a reference and a data beam to create an interference
pattern at a medium where the two beams intersect. This intersection causes a stable physical or
chemical change which is stored in the medium. This is the write sequence. During reading, the
action of the reference beam and the stored interference pattern in the medium recreates this data
beam which may be sensed by a detector array. The medium may be a rotating disk containing a
polymeric material, or an optically sensitive single crystal.
HISTORY OF HOLOGRAPHIC VERSATILE DISC
Holography was first discovered in 1947, but the techniques of holography didn't really advance
until the development of the laser in 1960. In 1968, the invention of white-light transmission
holography enabled holographs in ordinary white light and the mass production of the type of
holographs most commonly seen today.
Although holography was conceived in the late 1940s, it was not considered a potential
storage technology until the development of the laser in the 1960s. The resulting rapid
development of holography for displaying 3-D images led researchers to realize that
holograms could also store data at a volumetric density of as much as 1/ A3 .
If a thousand holograms, each containing a million pixels, could be retrieved every second, for
instance, then the output data rate would reach 1 Gigabit per second.Despite this attractive
potential and fairly impressive early progress research into holographic data storage died out in
the mid-1970s because suitable devices for the inputand output of large pixelated 2-D data pages.
In the early 1990s, interest in volume-holographic data storage was rekindled by the availability
of devices that could display and detect 2-D pages, including charge coupled devices (CCD),
complementary metal-oxide semiconductor (CMOS) detector chips and small liquid-crystal
panels. The wide availability of these devices was made possible by the commercial success of
hand-held camcorders, digital cameras, and video projectors. With these components in hand,
holographic-storage researchers have begun to demonstrate the potential of their technology in
the laboratory. By using the volume of the media, researchers have experimentally demonstrated
that data can be stored at equivalent areal densities of nearly 400 bits/sq. micron. (For
comparison, a single-layerof a DVD disk stores data at ~ 4:7 bits/sq. micron ) A readout rate of
10 Gigabit per second has also been achieved in the laboratory.
[4]

5. WORKING OF HVD
The process of creating a hologram begins with a focused beam of light -- a laser beam. This
laser beam is split into two separate beams: a reference beam, which remains unchanged
throughout much of the process, and an information beam, which passes through an image.
When light encounters an image, its composition changes (see How Light Works to learn about
this process). In a sense, once the information beam encounters an image, it carries that image in
its waveforms. When these two beams intersect, it creates a pattern of light interference. If you
record this pattern of light interference -- for example, in a photosensitive polymer layer of a disc
-- you are essentially recording the light pattern of the image.
To retrieve the information stored in a hologram, you shine the reference beam directly onto the
hologram. When it reflects off the hologram, it holds the light pattern of the image stored there.
You then send this reconstruction beam to a CMOS sensor to recreate the original image.
Most of us think of holograms as storing the image of an object, like the Death Star pictured
above. The holographic memory systems we're discussing here use holograms to store digital
instead of analog information, but it's the same concept. Instead of the information beam
encountering a pattern of light that represents the Death Star, it encounters a pattern of light and
dark areas that represent ones and zeroes.
The technique used is known as collinear holography, whereby two lasers, one red and the other
blue or green beams are collimated in a single beam. The red laser is used to read the servo
information from normal or regular CDs. The servo information is used to monitor the position
of the read head over the disk. The blue or green laser is used to read data encoded as laser
interference fringes from the holographic layer. There is a Dichroic Mirror layer between
holographic data and servo data which reflects the blue or green laser, while allowing the red
laser to pass through.
The green laser in the HVD reads data encoded as laser interference fringes from a holographic
layer near the top of the disc. A red laser is used as the reference beam to data reflects the green
laser while letting the red laser pass through. Holographic recording layer is formed on top of a
reflective layer. The Collinear Technology has allowed the HVD disc to have a reflective layer
on the substrate and address pits formed on this layer. This is used to read servo information. The
Aluminum reflective layer reflects the red light. The Dichroic layer reflects the green light.
Photopolymeric layer is the data containing layer.
The Holography System Development Forum provides (HSD Forum; formerly the HVD
Alliance and the HVD FORUM) testing and technical discussion of all aspects of HVD and
manufacturing. Members of the HVD Alliance include Fujifilm, Konica Minolta and Mitsubishi.
According to the Alliance, HVD will eventually replace DVD.
To increase capacity, holographic storage uses laser beams to store digital data in three
dimensions, rather than in two dimensions as in CD and DVD media. HVD is, essentially, a
holographic layer built on top of a conventional disc. The HVD process uses a blue-green laser
beam, used for reading and writing data, collimated (made parallel) with a red laser beam, which
is used for servo and tracking.
Holographic versatile disc (HVD) 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
[5]

6. 3.9 terabytes (TB) and a transfer rate of 1 gigabit per second (1 Gbps). At that capacity, an HVD
could store as much information as 830 DVDs or 160 Blu-Ray discs.
To increase capacity, holographic storage uses laser beams to store digital data in three
dimensions, rather than in two dimensions as in CD and DVD media. HVD is, essentially, a
holographic layer built on top of a conventional disc. The HVD process uses a blue-green laser
beam, used for reading and writing data, collimated (made parallel) with a red laser beam, which
is used for servo and tracking.
In the recording process, the initial laser is split into two beams. One of the beams passes
through a device called a spatial light modulator (SLM) and combines with the direct beam to
produce a hologram in the physical medium. To recover the data, another 532-nm laser is
directed into the hologram, which diffracts the laser beam. The resulting image constitutes an
optical reproduction of the original recorded data. A photosensitive semiconductor device
converts this optical data into the original digital files.
The first working HVD systems for the enterprise are expected to be shipped in 2006, with
consumer HVDs and drives to become available in 2008 or later. The initial target market is
high-volume mass storage, such as digital television (DTV) broadcasts and document libraries in
large businesses and government agencies.
To increase capacity, holographic storage uses laser beams to store digital data in three
dimensions, rather than in two dimensions as in CD and DVD media. HVD is, essentially, a
holographic layer built on top of a conventional disc. The HVD process uses a blue-green laser
[6]

7. beam, used for reading and writing data, collimated (made parallel) with a red laser beam, which
is used for servo and tracking.
In the recording process, the initial laser is split into two beams. One of the beams passes
through a device called a spatial light modulator (SLM) and combines with the direct beam to
produce a hologram in the physical medium. To recover the data, another 532-nm laser is
directed into the hologram, which diffracts the laser beam. The resulting image constitutes an
optical reproduction of the original recorded data. A photosensitive semiconductor device
converts this optical data into the original digital files.
The first working HVD systems for the enterprise are expected to be shipped in 2006, with
consumer HVDs and drives to become available in 2008 or later. The initial target market is
high-volume mass storage, such as digital television (DTV) broadcasts and document libraries in
large businesses and government agencies.
Members of the HVD Alliance include Fujifilm, Konica Minolta and Mitsubishi. According to
the Alliance, HVD will eventually replace DVD.
HVD is a storage media. It is the next generation optical disk technology still in a research
phase. Storage technologies must improve because of the rapidly increasing demand.HVD has
more storage capacity than HD DVD and Blu-Ray optical disk systems. HD DVD and Blu-Ray
optical disk systems have a storage capacity of 75 and 90 GB only. HVDs will have a storage
capacity of 3.9 terabytes (39,000 GB) and a data transfer rate of 1 GB/s. The concept of HVD
comes from inventor, Mr. Horimai’s long time experience in optical disk development and his
idea to combine collinear technology with the conventional optical disk technology. The main
use of Holographic versatile disc are data storage and for high definition video. HVD is the
technology in high-capacity, optical storage media.
[7]

8. Recording holographic page data on a rotating transparent disc has been reported before. Such
discs, however, are foreign to the conventional optical discs. Lacking the servo information, they
do not seem to have a commercial viability. On the contrary Optware has proposed Collinear
Holographic recording on a hologram disc the structure of which follows conventional optical
disc, i.e. preformatted disc with a reflective layer (disc with servo information).
HOLOGRAHIC RECORDING TECHNOLOGY
Holographic recording technology records data on discs in the form of laser interference fringes,
enabling existing discs the same size as today's DVDs to store more than one terabyte of data
(200 times the capacity of a single layer DVD), with a transfer rate of over one gigabit per
second (40 times the speed of DVD). This approach is rapidly gaining attention as a high-
capacity, high-speed data storage technology for the age of broadband.
The technology behind this is based on the following:
Current optical storage saves one bit per pulse, and the HVD alliance hopes to improve this
efficiency with capabilities of around 60,000 bits per pulse in an inverted, truncated cone shape
that has a 200 micrometer diameter at the bottom and a 500 micrometer diameter at the top. High
densities are possible by moving these closer on the tracks: 100 GB at 18 micrometers
separation, 200 GB at 13 micrometers, 500GB at 8 micrometers and a demonstrated maximum of
3.9 TB for 3 micrometer separation on a 12 cm disc.The system uses green laser, with an output
power of 1 watt, a high power for a consumer device laser. So a major challenge of the project
for widespread consumer markets is to either improve the sensitivity of the polymer used, or
develop and commoditize a laser capable of higher power output and suitable for a consumer
unit.
One of the real advantages of this new technology is storage:
It has been estimated that the books in the U.S. Library of Congress, one of the largest libraries
in the world, would contain a total of about 20 terabytes if scanned in text format. Neglecting
images, the content could be stored on a little more than 6 of these discs. At 15 meter resolution
and 32-bit colour (about the resolution found in Google Earth), a map of the land masses of Earth
would occupy just over 2 TB. Using MPEG4 ASP encoding, a 3.9 TB HVD could hold between
4,600–11,900 hours of video—just over one year of uninterrupted video at usual encoding rates.
The transfer rate is at an average of 1 gigabit/second, or 128 megabytes/second, around 6 times
the transfer rate for current 16x DVD storage.
Other technologies currently developed:
HVD is not the only technology in next-generation, high-capacity optical storage media.
InPhase Technologies has developed a holographic format they call Tapestry Media, capable of
storing up to 1.6TB with a data transfer rate of 120 MB/s. Hitachi Maxell, Ltd. plans to enter the
market by offering 300GB discs with a data transfer rate of 20 Mbit/s. With such a high end
storage capacity, it would seem like a better technology than either HD DVD or Blu-Ray Disc.
[8]

9. However, the reader currently costs approximately US$15,000, and a single disc currently costs
approximately US$120, and by 2010, will cost about US$100. The market for this format is
currently not the common consumer, but is instead for those with very large storage needs.
In late 1995 a joint university/industry/government consortium initiated the Holographic Data
Storage System (HDSS) programme, with the initial goals of developing several key components
for the system, including a high-capacity, high-bandwidth spatial light modulator used for data
input; optimised sensor arrays for data output; and a high-power red-light, semiconductor laser.
At the same time, the HDSS researchers were to explore issues relating to the optical systems
architecture (such as multiplexing schemes and access modes), data encoding/decoding methods,
signal processing techniques, and the requirements of target applications. Into the programme’s
final year, progress has been such that consortium member – IBM Research Division – believed
that holograms could hold the key to high-capacity data storage in the next millennium.
In holographic data storage, an entire page of information is stored at once as an optical
interference pattern within a thick, photosensitive optical material. Therein lie the reasons why
holographic data storage is able to both break through the density limits of conventional storage
and achieve data transfer rates significantly higher than current optical storage devices:
unlike other technologies that record one data bit at a time, holography allows a million bits of
data to be written and read in parallel with a single flash of light, and
it is by going beyond recording only on the surface, to recording through the full depth of the
medium that holographic data storage is able to break through the density limits of conventional
storage.
The combination of high storage densities, fast transfer rates, with durable, reliable, low cost
media, make holography poised to become a compelling choice for next-generation storage
solution to the data archival requirements of the commercial, medical, governmental and
broadcast industries.
Holographic storage uses two laser beams, a reference and a data beam to create an interference
pattern at a medium where the two beams intersect. This intersection causes a stable physical or
chemical change which is stored in the medium. This is the write sequence. During reading, the
action of the reference beam and the stored interference pattern in the medium recreates this data
beam which may be sensed by a detector array. The medium may be a rotating disk containing a
polymeric material, or an optically sensitive single crystal.
Tokyo-based Optware Corporation, a leading developer of Holographic Versatile Disc (HVD)
storage products, has developed a system – referred to as collinear holography – in which the
reference and information beams are handled as a pencil of coaxial light, rather than the two-
beam interference method widely used in the past. This breakthrough mechanism has led to a
dramatic simplification and downsizing of the previously bulky and complicated systems
required to generate holograms, and in early 2005 ECMA created a technical committee to
develop a standardisation strategy for Holographic Information Storage (HIS) systems, that was
initially based upon Optware’s Collinear Technologies.
One of the major challenges in the area of holographic data storage has been the development of
suitable storage materials. Holographic media must satisfy stringent criteria, including high
dynamic range, high photosensitivity, dimensional stability, optical clarity and flatness, non-
destructive readout, millimetre thickness, and environmental and thermal stability. Many groups
centred in large commercial research organisations had looked at this problem, and most had
given up without success.
[9]

10. However, one of those that that persevered was InPhase Technologies, founded in December
2000 as a Lucent Technologies venture, spun out of Bell Labs research. Eventually, their efforts
were to bear fruit, with the development of a new class of photopolymer materials which
satisfied the criteria for a commercial viability, and which was to lead to a successful public
demonstration of a prototype of the very first holographic data storage drive, during 2005.
Typical photopolymers use a single chemistry for bonding molecules together to form the media
and to perform the recording. The InPhase polymer system utilises materials that use two distinct
chemistries that are independent yet compatible. One chemistry is used to form the media and to
control the mechanical, manufacturing, and archive life parameters. The second chemistry is
used during the recording process. These two chemistries do not interact or interfere with each
other, thus enabling high dynamic range with extremely good dimensional stability during
recording.
Dubbed the Tapestry Drive, the first commercial units are expected to be delivered to OEMs in
October 2006. The first drives in the family will be WORM devices with a capacity of 300GB on
a single 12cm removable disk. InPhase expect to increase this to 800GB in late 2007 and to
1.6TB in 2010. All this family of drives will be fully backward compatible.
One of the technical problems in making holographic versatile disc systems affordable lies with
the complex systems necessary to get the laser beams aligned for accuracy. For this technology
to work well the beams of light must intersect perfectly. Currently, the two beams are directed
toward the image at different angles. Newer experimental technology focuses on sending the two
beams on the same line, which means they strike the recording layer at the same angle.
A red laser is used as the reference beam to read servoinformation from a regular CD-style
aluminium layer near the bottom. Servoinformation is used to monitor the position of the read
head over the disc, similar to the head, track, and sector information on a conventional hard disk
drive. On a CD or DVD this servoinformation is interspersed amongst the data. A dichroic
mirror layer between the holographic data and the servo data reflects the green laser while letting
the red laser pass through. This prevents interference from refraction of the green laser off the
servo data pits and is an advance over past holographic storage media, which either experienced
too much interference, or lacked the servo data entirely, making them incompatible with current
CD and DVD drive technology.
Most of us think of holograms as storing the image of an object, like the Death Star pictured
above. The holographic memory systems we're discussing here use holograms to store digital
instead of analog information, but it's the same concept. Instead of the information beam
encountering a pattern of light that represents the Death Star, it encounters a pattern of light and
dark areas that represent ones and zeroes.
NEED OF HVD
 Multimedia- a single minute of compressed video takes upto 12 Mbytes.
 Data Warehouses- large corporations warehouses now taking more than 2Tbytes.
 World Wide Web- one vendors high end Web server packs 128Gbytes of Disc.
[10]

11. These interference fringes are recorded if the two beams have been
overlapped within a suitable photosensitive media, such as a photopolymer or inorganic
crystal or photographic film. The bright and dark variations of the interference pattern
create chemical and/or physical changes in the media, preserving a replica of the
interference pattern as a change in absorption, refractive index or thickness.
COLLINEAR HOLOGRAPHY
HVD uses a technology called 'collinear holography,' in which two laser rays, one blue-
green and one red, are collimated into a single beam. The role of the blue-green laser is to
read the data encoded in the form of laser interference fringes from the holographic layer
on the top, while the red laser serves the purpose of a reference beam and also to read the
servo info from the aluminum layer - like in normal CDs - near the bottom of the disk.
The servo info is meant to monitor the coordinates of the read head above the disk (this is
similar to the track, head and sector information on a normal hard disk drive).
How HVD Compares
While HVD is attempting to revolutionize data storage, other discs are trying to improve upon
current systems. Two such discs are Blu-ray and HD-DVD, deemed the next-generation of
digital storage. Both build upon current DVD technology to increase storage capacity. All three
of these technologies are aiming for the high-definition video market, where speed and capacity
count. So how does HVD stack up?
Blu-ray HD-DVD HVD
Initial cost for recordable disc Approx. $18 Approx. $10 Approx. $120
Initial cost for recorder/player Approx. $2,000 Approx. $2,000 Approx. $3,000
Initial storage capacity 54 GB 30 GB 300 GB
Read/write speed 36.5 Mbps 36.5 Mbps 1 Gbps
Because HVD is still in the late stages of development, nothing is written in stone; but you've
probably noticed that the projected introductory price for an HVD is a bit steep. An initial price
of about $120 per disc will probably be a big obstacle to consumers. However, this price might
not be so insurmountable to businesses, which are HVD developers' initial target audience.
[11]

12. Optware and its competitors will market HVD's storage capacity and transfer speed as ideal for
archival applications, with commercial systems available as soon as late 2006. Consumer devices
could hit the market around 2010.
ADVANTAGES OF HVD
High Storage capacity of 3.9 terabyte (TB) enables user to store large amount of data.
Records one program while watching another on the disc.
Edit or reorder programs recorded on the disc.
Automatically search for an empty space on the disc to avoid recording over a program
Users will be able to connect to the Internet and instantly download subtitles and other
Interactive movie features
Backward compatible: Supports CDs and DVDs also.
The transfer rate of HVD is up to 1 gigabyte (GB) per second which is 40 times faster than DVD
An HVD stores and retrieves an entire page of data, approximately 60,000 bits of information, in
one pulse of light, while a DVD stores and retrieves one bit of data in one pulse of light.
High storage capacity
Selectable capacity recording format
Good read/write performance.
DISADVANTAGES
The initial price of the player and discs themselves are far more expensive than HD-DVD or Blu-
ray.
It could be argued that the public is not entirely ready for even the costs or benefits of Blu-ray or
HD-DVD, much less HVD.
PRESENT STATUS OF HVD
HVD storage capacity: 100gb
Structure is similar to CD/DVD
Data transfer rate 125mbps
It is expensive
[12]

13. FUTURE SCOPE OF HVD
Storage capacity:3.9TB
Data transfer rate:1gb/s
Backward Compatible Drives
Holographic Cards
CONCLUSION
The Information Age has led to an explosion of information available to users. While
current storage needs are being met, storage technologies must continue to improve in
order to keep pace with the rapidly increasing demand. Storing
information throughout the volume of a medium―not just on its surface •offers an
intriguing high-capacity alternative. Holographic data storage is a volumetric approach
which, although conceived decades ago, has made recent progress toward practicality
with the appearance of lower-cost enabling technologies, significant results from
longstanding research efforts, and progress in holographic recording materials.
HVD gives a practical way to exploit the holography technologies to store data upto 3.9
terabytes on a single disc. It can transfer data at the rate of 1 Gigabit per second. The
technology permits over 10 kilobits of data tobe written and read in parallel with a
single flash. So an HVD would be a successor to today's Blu-ray and HD-DVDtechnologies.
REFERENCES
www.google.com
www.siemen.com
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