Contents Introduction Magnetic and conventional optical data storage technologies are approaching physical limits beyond which individual bits may be too small or too difficult to store Holographic data storage is an approach of storing information throughout the volume of a mediumnot ju ID: 577498
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HOLOGRAPHIC DATA STORAGE
Slide2
ContentsSlide3
Introduction
Magnetic and conventional optical data storage technologies are approaching physical limits beyond which individual bits may be too small or too difficult to store.
Holographic data storage is an approach of storing information throughout the volume of a medium—not just on its surface.
With the rapidly increasing demand for increased storage capacity in a smaller space, this technology offers an economy in price.
Slide4
Features
Next – Next generation Technology
1 HVD = 5800 CDs = 830 DVDs = 160 Blu-ray
Media type : Ultra-high density optical disc
Encoding : MPEG-2, MPEG-4 AVC (H.264), and VC-1
Capacity theoretically up to 3.9 TB
Developed by HSD Forum
Usage : Data Storage,
: High-
defination
video and the possibility of Ultra-high
defination
video
permits over 10 Kbits of data to be read and written in
parallel with a single flash Slide5
What Is Hologram ?
A hologram is a recording of the optical interference
pattern that forms at the intersection of two
coherent optical
beams
Signal beam
Reference beam
on the holographic medium.Slide6
Types of Holograms
Transmission Hologram
Can be used to store data
Uses coherent light
Reflection Hologram
The kind you find on credit cards
Uses white lightSlide7
Holography vs Photography
Black and white photograph
Intensity
Color
photograph
Intensity and wavelength
Hologram
Intensity, phase, and sometimes wavelengthSlide8
Review of InterferenceSlide9
Creating HologramSlide10
Reconstructing the ImageSlide11
Qualitative Explanation of Storage
Reference beam
Object image
Resultant pattern
Stored in filmSlide12
Qualitative Explanation of Reconstruction
Reference beam
Stored in film
ReflectionSlide13
Recording DataSlide14
Spatial Light Modulator(SDM)
Translates electronic data (0’s and 1’s) into optical pattern of light and dark
pixcels
Data is arranged in an array similar to a checker board of usually 1 million bits
By varying the angle of the reference beam ,wavelength or media position, many holograms can be stored in the same volume of storage materialSlide15
Reading DataSlide16
Pattern Left on MediaSlide17
HVD Technology
HVD uses a technology called ‘collinear technology’
Two Laser rays one blue-green and one red are used
The role of blue-green laser is to read the data encoded the form of laser interference fringes from the holographic layer
The red laser serves the purpose of a reference beam and also to read the servo info from the aluminum layerSlide18Slide19
Read only HVD Read\Write HVD
supports some irreversible photochemical reaction triggered by the bright regions of the optical interference pattern
Material diffuses from darker to brighter regions so that short monomer chains can bind together to form long molecular chains
uses inorganic photorefractive crystals
Electrons get photo-excited at the bright fringes, diffuse or drift and are re-trapped at a dark fringe
Trapped charge can be rearranged by later illumination, so it is possible to erase recorded holograms Slide20Slide21
Current State of Technology
Storage
and Cost
CD-ROM:
783 MB to 1.3 GB
– 10 cents
DVD+DL:
5 GB to 30 GB
- $3
Blu-Ray DL:
25 GB to 50 GB
- $30
InPhase Tapestry: 300
GB
- $250
Hard disk: 1
TB
- $300
HVD (future): 4
TB Slide22
Current State of Technology
Tansfer rates and Recordable Player Approx Cost
CD-ROM 52x: ~ 5
MB/second --$200
DVD 16x: ~ 20
MB/s --$ 2000
InPhase Tapestry: 20
MB/sec
B
lu-Ray
and HDDVD: ~ 30
MB/sec --$2000
7200 rpm Hard disk: 80
MB/sec
HVD: 1 GB/sec --$3000Slide23
Interesting Facts
It has been estimated that books in the U.S. Library of Congress, the largest library in the world, could be stored on 6 HVD’s
The pictures of every landmass on Earth – like the one shown in Google Earth can be stored on two HVD’s
With MPEG4 ASP encoding
, a HVD can hold anywhere in between 4,600 to 11,900 hours of
video, which is enough for non-stop Playing for a yearSlide24Slide25Slide26