Holographic Storage
Physics 496
Michael Atkinson
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Why Holographic Storage?
Storage Density media stores data in whole volume
Speed parses many bits at once
Reliability Good shelf life High number of write cycles
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Outline
Holography Concepts
Refractive index modulation
Storing data
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Types of Holograms
Transmission HologramCan be used to store dataUses coherent light
Reflection HologramThe kind you find on credit cardsUses white light
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Holography vs Photography
Black and white photograph Intensity
Color photograph Intensity and wavelength
Hologram Intensity, phase, and sometimes wavelength
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Review of Interference
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Creating Hologram
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Pattern Left on Media
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Reconstructing the Image
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Qualitative Explanation of Storage
Reference beam Object image Resultant pattern Stored in film
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Qualitative Explanation of Reconstruction
Reference beam Stored in film Reflection
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Photorefractive effect
Electrons gain energy from light
Leave Valence band, can move freely
Diffuse toward dark areas
When beams removed, electrons settle and we have internal net electric fields
Index of refraction changed due to electro-optic effect
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Intensity Threshold
EValence
EConduction
Object Image
Reference Beam
Object Image
Reference Beam
External electric field
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Storing Data
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Reading Data
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Current State of Technology
Storage CD-ROM: 800 Mbytes – 10 centsDVD+DL: 8.4 Gbytes - $3Blu-Ray DL: 50 Gbyte - $30InPhase Tapestry: 300 Gbyte - $250Hard disk: 1 Tbyte - $300HVD (future): 4 Tbytes
Transfer ratesCD-ROM 52x: ~ 5 Mbit/second DVD 16x: ~ 20 Mbit/sInPhase Tapestry: 20 Mbit/secBlu-Ray and HDDVD: ~ 30 Mbit/sec7200 rpm Hard disk: 80 Mbit/sec
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References Physics for Scientists and Engineers with Modern Physics – Vol 2, Serway and Jewett
International Conference on Holography, Optical Recording, and Processing of Information: http://spiedl.aip.org/dbt/dbt.jsp?KEY=PSISDG&Volume=6252&Issue=1
Thermally sensitized optical recording in azobenzene polymers• D.Illieva, M. Ivanon, T. Petrova, V. Dragostinova, G. Minchev, T. Todorov, L.
Nikolova Refractive data of optical plastics for laser applications
• N. Sultanova, S. Kasarova, C. Ivanov, I. Nikolov Pulse Recording Dynamics of Diffraction Gratings in Xanthene Dyes Sensitized
Photopolymer Material• E. Vasilyev, V. Shelkovnikov, E. Pen, A. Plechanov
Holographic recording in nanoparticle-doped photopolymer• I. Naydenov, H. Sheriff, S. Mintova, S. Toala
http://hyperphysics.phy-astr.gsu.edu/hbase/optmod/holcon.html http://www.research.ibm.com/journal/rd/443/ashley.html http://www.howstuffworks.com/holographic-memory.htm http://en.wikipedia.org/wiki/Holography http://en.wikipedia.org/wiki/Holographic_Versatile_Disc http://www.inphasetechnologies.com/downloads/pdf/products/
2007TapestryProductBrochure.pdf
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Image Sources
Slide 2: ad from slashdot.com Slide 6:
http://sol.sci.uop.edu/~jfalward/lightinterference/lightwaveshowingelecvector.jpg http://www.chem.wisc.edu/~newtrad/CurrRef/BDGTopic/BDGFigs/3_13cdfere.gif
Slide 7: http://hyperphysics.phy-astr.gsu.edu/hbase/optmod/imgopm/holo2.gif
Slide 8: http://hyperphysics.phy-astr.gsu.edu/hbase/optmod/modpic/holripp.jpg
Slide 9: http://hyperphysics.phy-astr.gsu.edu/hbase/optmod/imgopm/holo3.gif http://www.research.ibm.com/journal/rd/443/ashle2.gif
Slide 10: drawn by me
Slide 11: drawn by me
Slide 13: taken from Thermally sensitized optical recording in azobenzene polymers, D.Illieva, M. Ivanon, T. Petrova, V.
Dragostinova, G. Minchev, T. Todorov, L. Nikolova Slide 14:
http://static.howstuffworks.com/gif/holo-memory.gif Slide 15:
http://static.howstuffworks.com/gif/holo-memory2.gif Slide 16:
http://www.inphase-technologies.com/images/products/drive-media_lg.jpg Slide 19:
http://physicsweb.org/objects/world/13/7/7/pw-13-07-07fig4.gif
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Questions?
