Contents2 Introduction to Holographic Memory History of the Holographic Memory Components of Holographic Memory Basics of workingWriting to diskReading from disk Spatial Light Modulator Storing techniques Properties of Holographic Data Storage Applications of Holographic Memory Pros and Corns of the system Conclusion References5/22/2013
Introduction to HolographicMemory Holographic memory is a developing technology that haspromised to revolutionize the storage systems. Holographic memory is an advanced optical storagedevice that can store information in the form ofholographic image. A method of producing a three-dimensional image of anobject by recording on a photographic plate or film thepattern of interference formed by a split laser beam andthen illuminating the pattern either with a laser or withordinary light.3 5/22/2013
History of Holographic Memory Scientist Pieter J. Van Heerden proposed the idea ofholographic(three-dimensional) storage in 1940 It is invented in 1947 by the Hungarian-British physicistDennis Gabor (1900-1979), who won a Nobel Prize forhis invention in 1971.4 5/22/2013
5HVD technology5/22/20131. Green writing/reading laser(532 nm)2. Red positioning/addressinglaser (650 nm)3. Hologram (data)4. Polycarbon layer5. Photo polymeric layer (data-containing layer)6. Distance layers7. Dichroic layer (reflectinggreen light)8. Aluminum reflective layer(reflecting red light)9. Transparent base
6Cont..• Holographic Versatile Disc(HVD) is an optical disktechnology still in research stage which would hold up to3.9 TB of information• The HVD also has a transfer rate of 1 gigabyte/s• It is a technique that can store information inside crystalsor photopolymers.5/22/2013
Components of HolographicMemory71. Blue-green Argon Laser2. Beam splitters to spilt the laser beam3. Mirrors to direct the laser beams4. LCD panel (spatial light modulator)5. Lenses to focus the laser beams6. Lithium-niobate crystal or photopolymer7. Charge coupled device camera5/22/2013
10SLM A Spatial Light Modulator is used for creatingbinary information out of laser light. The SLM is a2D plane, consisting of pixels which can be turned onand off to create binary 1’s and 0’s. An SLM can usually be refreshed at rates of about 1000frames per second5/22/2013
11Storing TechniquesMultiplexing Angular Multiplexing : By modifying the angle of a sourcebeam, large amount of data is stored in the volume.5/22/2013
12Cont.. Wavelength Multiplexing : Alters the wavelength of sourceand reference beams between recordings Spatial Multiplexing : Changing the point of entry of sourceand reference beams into the recording medium5/22/2013
18How HVD compares with other storagedevice? 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 thenext-generation of digital storage.HD-DVD Blu-ray HVDInitial cost forrecordable discApprox. $10 Approx. $18 Approx. $120Initial storagecapacity30 GB 54 GB 300 GB5/22/2013
19 5/22/2013Applications of Holographic Memory• Data Mining : Retrieval of data is very fast and storinglarge amount of data in a single disk.• Petaflop computation : performs thousand trillionfloating point operations per second.• Holographic memory can be used as an extendedDRAM with 10ns access time.
20Advantages of Holographic Memory1. Resistance to damage - If some parts of the mediumare damaged, all information can still be obtained fromother parts.2. Efficient retrieval - All information can be retrievedfrom any part of the medium.3. High storage capacity of 3.9 terabyte(TB)4. While reading data the entire page of data can beretrieved quickly and at one time .5. Backward compatible, supports CD’s and DVD’s also.5/22/2013
21Disadvantages of Holographic Memory5/22/2013• Manufacturing cost of HDSS is very high.• There is a lack of availability of resources which are neededto produce HDSS.• Writes in the same fashion can degradeprevious writes in the same region of the medium.
22Cont..5/22/2013• The re-illuminated reference beam used to retrieve therecorded information, also excites the donor electrons anddisturbs the equilibrium of the space charge field in a mannerthat produces a gradual erasure of the recording.• The crystal used as the photographic filament must haveexact optical characteristics.
23Holographic Memory Systems Fuji Photo Film Imation Toshiba Konica-Minolta Matsushita/Panasonic Memory-Tech Micron Mitsubishi Chemical Nippon Paint OPTWARE TV Asahi Corporation TV Tokyo Corporation Warner Bros. Disney Universal Pioneer Sanyo JVC NEC InPhase Technologies Maxell AprilisSOME OF THE CURRENT PLAYERS5/22/2013
25Conclusion HVD will soon replace present DVDs. It is currently supported by more than 170 of the worldsleading consumer electronics, personal computer,recording media, video game and music companies.5/22/201325