Transcript Holographic Optical Data Storage

The Future in Data Storage
 Holographic Optical Data Storage (HODS) or
Holographic Data Storage System (HDDS)
–
–
–
–
The Revolutionary data storage technology
Uses images (holograms) rather than bits to store data
Images imposed in material
Uses a combination of Lasers & Optical materials to
achieve this .
– This is a Volumetric approach.
Pieter J. van Heerden first proposed the idea of holographic
(three-dimensional) storage in the early 1960s.
 A decade later, scientists at RCA Laboratories demonstrated
the technology by recording 500 holograms in an iron-doped
lithium-niobate crystal.
The advent of Semiconductor & magnetic memories stalled its
research for much time but it is now picking up momentum.
Why Do We Need This?
 “For Internet applications alone, industry estimates are that
storage needs are doubling every 100 days”
-Nelson Diaz, Lucent Technologies
 “Optoelectronics Industry and Technology Development
Association projects that by the year 2010, a storage system
serving an average LAN will need … 10 TB and a WAN
server will require 100 TB to 1 petabyte …of storage”
- Red Herring
Overview of HODS
The Practical Setup
The Green Argon Laser
• Laser light is a green
514.5-nm line of an
argon-ion laser.
• The system is equipped
with an argon (514.5-nm)
or a krypton (676-nm)
laser
• Optical power delivered
to the apparatus prior to
the object/reference
beam splitter is as much
as 100-400 mW .
What is SLM ?
• SLM - Spatial Light
Modulator.
• SLM consists 1-D or 2-D
arrays of light modulating
elements.
• SLM converts the digital
data 1’s or 0’s into a 2-D
array of bright & dark
spots.
• SLM is used to imprint the
data on the object beam.
About Lithium Niobate Crystal
• Chemical Formula- LiNbO3.
• It has high photorefractive sensitivity &
stability.
• It has trigonal structure.
• Molecular weight - 147.9.
• Band gap - 4eV
What is CCD ?
• CCD - Charge Coupled
Device.
• Its structure was
proposed in 1969 by
Boyle & Smith.
• CCD is a light sensitive
device.
• CCD converts pixels in
images into electric
charge.
• CCD contains a separate
value for each colour.
Storage inside the Photosensitive Medium
Storage of one bit of
information as a Hologram.
a) Superposition of spherical
wave from one bit with a
coherent plane wave reference
beam forming an interference
pattern.
b) Exposure of a photosensitive
medium to the interference
pattern.
c) Record of the interference
grating, stored as changes in the
properties of the medium.
Recording
• Data stream is sent to the SLM as 0’s and
1’s.
– Forms a “checkerboard” pattern
– 1’s transmit light, 0’s block light
• Beam is split
–Light passing through SLM is the signal
(object) beam
–Reflected beam is the reference beam
• Beams interfere in the medium to produce
hologram much like before
Recording by Figure
Reading
• Beam no longer split
• Reference beam is diffracted off the
recorded grating (hologram)
– Reconstructs matrix
• Projected using optic onto CCD
– Converts into data stream
Reading by Figure
Impacts
•
The everyday user might not notice the impact other than more space
on his/her computer.
•
Big benefactors are big business and internet
– Parallel data storage and retrieval allows for very fast data excess for number
crunching and experiments (much faster computation times).
– Much faster data access for internet servers as well as much larger storage
densities.
– Cheaper cost per Megabyte once mainstream.
•
Data storage for libraries, documents and so forth will be cheaper and
take up less space and access will be much faster.
Future Applications
• Imagine the capability of
6,840 raw uncompressed
high
quality
Video/TV
hours, or 2,100,000 chest xrays, or nearly 10,000,000
high-resolution images, or
30,000 four-drawer filing
cabinets of documents or
20,000 DVD'S Worm's or
4,000
BLU-Ray
Worm
disk's on ONE 10 Terabyte
3.5 in. removable disc.
Future Applications
Long Term !
• Eventually HODS’s may take over
magnetic and optical devices all together
– DVD’s with 10 terabytes on them !
– Less need for compression techniques
(depending on internet communications)
– Even smaller computers (hard drive one of
the largest components)
– Less power to drive = longer lasting
laptops
Market Prospects
• Current storage memory market
exceeds $100 billion dollars
worldwide
– $47 billion is solely hard disk, $42
billion magnetic tape drives, $6
billion optical disk
• This is growing at 40% a year
(1998)
• HODS has the possibility of taking
over this entire market
– Can assimilate all these data
storage types
– Little to no competitive
alternatives on the horizon
Who is Involved…
• InPhase Technologies, venture of Lucent
Technologies
– Exclusive purpose is to develop high-performance
holographic data storage media
– Seem to be leaders in viable product, near useable
solution
• Government and other participants donate $32
million for research
– Large majority of research focused at Standford and
IBM’s Almaden Research Facility
Interesting Facts
• With predicted technology a 1cm3 laser
cube is equal to:
- 6,944,440 1.44MB floppy discs
- 14,286 700 MB CD-ROM’s
- 40 250 GB hard drives
- 25 million books of the Library of Congress(US)
Conclusion
• Built on technology that’s around for 40+ years
• HODS may be the future of data storage
– HUGE capacity, Very fast, Smaller
– Parallel processing
• Current storage methods nearing their
fundamental limits of storage density
• Stationary parts for some techniques
• Meets the demand for a capacity hungry society
• Large market and little new competition
Further Research/Bibliography
• www.lucent.com/press/0101/010130.bla.html
• http://www.research.ibm.com/research/press/holographic.html
• http://www.research.ibm.com/journal/rd/443/ashley.pdf
• http://www.imation.com/about/news/newsitem/0%2C1233%2C29
8%2C00.html
• http://www.pitt.edu/~drew1/2089/holo.htm
• http://www.sciam.com/2000/0500issue/0500toigbox5.html
Thank you for listening to
my presentation!
The
The future
future is
is here
here !