The first papers on holographic storage were published in 1963 Holographic storage is using the entire medium instead of a few layers.You use 2 laser beams instead of one with one carrying the data and the other being a reference beam.
The Two-Axis method was studied for many years with little success.The biggest problem was finding an adequate recording medium that offered precise recording. Then Optware Corporation, based in Yokohama, Japan, invented the Collinear Holography method which puts all the lasers and optics on one side of the disk. This made it backward compatible with CD’s and DVD’s plus it included a reflective layer with an encryption process called Servo.
Video from GE Global Research describing Holographic Data Storage.That explains what they are wanting to achieve in this technology. Bottom line – cheap method that stores a lot of data
So how do they actually get data onto a holographic disk.Data is converted into binary code just like we do today.Computer binary code is converted into optical patterns of dark and light pixels to represent the 1’s and 0’s.
Spatial light modulators (SLM) are pixelated input devices (liquid crystal panels), used to imprint the data to be stored on the object beam. LargeSpatial Light Modulator’s (SLMs) are placed on overhead projectors to project computer monitor contents to the screen like what is being used today to convey this presentation onto the wall.
Animation showing the information beam and the data beam of the Holographic laser. Where the two beams intersect is where the data is written.By adjusting the reference beam angle, wavelength (color), or media position, a multitude of holograms (theoretically, several thousand) can be stored on a single volume.
Illustration of what the holographic image looks like as it is being written onto the recording layer.
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.The servo beam in the HVD system is at a wavelength that does not photosensitize the polymer recording medium. The structure of the disc places a thick recording layer between two substrates and incorporates a dichroic mirror that reflects the blue-green light carrying the reference patternbut allows the red light to pass through in order to gather servo information.
The HVD (Holographic Versatile Disc) format is currently promoted by the HVD Alliance who was formed to discuss the standards for this medium. Optware is also working to standardize the HVD format through the Ecma International industry association (www.ecma-international.org), which develops standards for Information and Communication Technology (ICT) and Consumer Electronics (CE).
Conventional Holography required the “Stop & Go” method of recording while the Collinear allows much more overlapping and simultaneous recording.The resulting hologram image reappears only when the two beams are realigned at an extremely precise point in the disk, so that big chunks of data can overlap without interfering with each other.
Animation showing the writing process.
Animation showing the reading process.
There are several reasons for the interest in holographic data storage. The biggest and utmost being the demand for more storage from various industries now that everything is digitized.
Dentists are using digital x-rays of teethOptometrists are using digital retinal scansDoctors and the medical field in general are going digital in all their scans.Data Warehousing.Any field that uses large amounts of data which needs to be archived.So the demand for storage space to archive all this additional information is increasing.
Capacity comparison between DVD’s and HVD’s.
The Voyager Golden Records are phonograph records which were included aboard both Voyager spacecraft, which were launched in 1977. They contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form, or for future humans, who may find them. It contained 116 images and a variety of natural sounds, such as those made by surf, wind, and thunder, and animal sounds, including the songs of birds and whales. To this they added musical selections from different cultures and eras, spoken greetings in fifty-five languages. Just think what they could put on a holographic disk (like a dictionary).
Holographic storage records and reads out data in a massively parallel manner, unlike the serial “one bit at a time” approach of traditional technologies. Digital data is stored and recovered as million-bit blocks rather than as single bits, enabling ultrafast data-transfer rates. This means a photograph can be saved in it’s entirety in one flash of light.You are literally recording data at the speed of light.
One bit at a time vs. entire page (60,000 bits) at a time.Flashes of light compared to actually burning the medium.
Archival Life expectancy is an estimated figure do to the environmental conditions that can affect a disk along with the quality and care in storing the disk. Virtually all CD-Rs tested indicated an estimated life expectancy beyond 15 years. Only 47 percent of the recordable DVDs tested indicated an estimated life expectancy beyond 15 years. Some had a predicted life expectancy as short as 1.9 years. Exposure to humidity, temperature, sunlight, mishandling, etc. along with the quality of the recording medium will affect the life expectancy.Counterpoints to this claim are that the evolution of data reader technology changes every ten years; therefore, being able to store data for 50–100 years would not matter if you could not read or access it.
For mass production, holographic media can be replicated very efficiently in one simultaneous transfer from a master. But once written, the replicated discs cannot be used as masters for further copying.HVD also includes servo data. The servo beam in the HVD system is at a wavelength that does not photosensitize the polymer recording medium. By adjusting one of its laser beams, Collinear technology can provide a physical level of on-disk encryption during recording and reading, which holds great promise for digital rights management and other applications requiring high levels of security.
The servo beam in the HVD system is at a wavelength that does not photosensitize the polymer recording medium. The introduction of this mechanism enabled reduced pickup size, elimination of vibration isolators, high-level compatibility with DVD and CD discs and low-cost operation, effectively obliterating the remaining obstacles to full commercialization.
Servo coding is placed in with the red laser beam which is able to penetrate the layers to the reflective layer where the servo information is gathered.
Almost the entire HDSS device can now be made from off-the-shelf components, which means that it could be mass-produced.However, up till now, there was no adequate recording medium to use – kind of like being all dressed up with no place to go.
A digital micro-mirror device, or DMD, is an optical semiconductor that is the core of DLP (Digital Light Processing) projection technology used in some TVs and video projectors.
CMOS (complimentary metal-oxide semiconductor) convert light into electrons.CMOS traditionally consumes little power.CMOS chips can be fabricated on just about any standard silicon production line, so they tend to be extremely inexpensive.
Optware’s HVD Pro Series 1000 Magnum HVD device.Holographic drives are projected to initially cost around US $15,000, and a single disc around US $120 –180, although prices are expected to fall steadily.
Key partners that have supplied the parts needed to build a holographic data storage unit.Founding members include CMC Magnetics (manufacturer of optical storage media), Fuji Photo Film (imaging media), Nippon Paint (paints and coating industry), Pulstec (test equipment), Toagosei (chemicals, photoresists, acrylic plastics, etc.) and Optware (research). Toshiba, Matsushita and Konica Minolta have also supported the HVD format.
Various on-line sources were used to create this presentation.
Expected (hoped) to hit the market by 2019.
Holographic data storage
Three dimensional or “holographic” datastorage involves using the entire mediafor storage, not just a few layers like wecurrently use today.The process is accomplished by usingtwo laser beams, instead of one, towrite data to the disk.
1. The object is converted into binary code of 1’s and 0’s like we use today.2. Next, the 1’s and 0’s are converted into a matrix of light and dark squares.
3. Those light and dark squares are then electronically sent to a spatial light modulator (SLM).4. The laser beam then shines through the spatial light modulator (SLM).5. Pixels of the spatial light modulator filter (block or allow) the light thus encoding the data into the laser beam.
Many disk prototypeshave been looked at overthe years, however, theindustry standard hasnow accepted havingthe HVD disk include areflective layer in order tobe backward compatibleand to assist withtracking of the writebeam.
“Stop and Go” “On the Fly”Conventional Holography Collinear Holography
Recording ProcessReference Pattern Information Pattern SLM Media Lens
In today’s world, digital media is becoming more and more common and is requiring more storage to meet the new demands. More industries are now using digital storage than ever before.200 DVD’s can fit on one 1 TB holographic disk with a future capacity of 6 terabytes.
IBMs test platforms can store up to 390 bits per square micron (a micron is a millionth of a metre). DVDs, by contrast, have a storage density of about five bits per square micron. DVD DVD Blu-Ray Blu-Ray HVDNumber of Layers Single Dual Single Dual 200+/-Recording Capacity 4.7GB 9.4GB 25GB 50GB 1TBData Transfer Rate 11.08Mb/s 11.08Mb/s 36Mb/s 36Mb/s 1GB/s
It has been estimated that all the books in the U.S. Library of Congress, could be stored on six (6) HVDs.The pictures of every landmass on Earth (Google Earth for example) can be stored on two (2) HVDs.With MPEG4 ASP encoding, a HVD can hold between 4,600 to 11,900 hours of video, which is enough for non-stop playing for a year.
Holography allows a million bits of data to be written and read out in single flashes of light, enabling data transfer rates as high as a billion bits per second (fast enough to transfer a DVD movie in about 30 seconds).
HVD’s have an estimated archival life expectancy of at least 50 years or more compared to CD/DVD archival life of 2 to 5 years (even though published life expectancies are often cited as 10 to 25 years or longer for optical media, it depends on the storage conditions and quality of the disks).
HVD storage also offers interesting possibilities for dataprotection. For mass production, holographic media canbe replicated very efficiently in one simultaneoustransfer from a master. But once written, the replicateddiscs cannot be used as masters for further copying.By adjusting one of its laser beams, Collineartechnology can provide a physical level of on-diskencryption during recording and reading, which holdsgreat promise for digital rights management and otherapplications requiring high levels of security.
Low cost materials needed to comeavailable which are just now happeningdue to other industries utilizing newtechnology.Development of neededcomponents, in fields outside thestorage industry, have brought the costdown making it financially viable toproceed.
Green lasers now used in the medical, cable TV, and printing industries are attractive recording sources due to their small size, ruggedness and low cost.Digital micro-mirror devices appearing in new types of displays are ideal spatial light modulators (SLM). This overhead projector for instance uses a SLM.
The CMOS active pixel detector arrays emerging in digital photography exhibit the rapid access and data transfer properties required for holography. CMOS sensors were originally proposed for the detection of visible light in cameras. In the holography field, they can detect the light patterns that are stored on the disks.
The Economist, Holographic data storage, Jul 31, 2003, http://www.economist.com/node/1956881 General Electric Global Research InPhase Technologies, Longmont, Colorado, http://www.inphase- technologies.com/ Wikipedia – Holographic Data Storage, http://en.wikipedia.org/wiki/Holographic_data_storage Bell Laboratories Physical Sciences Research, http://www.bell- labs.com/org/physicalsciences/projects/hdhds/1.html How Holographic Memory Will Work by Kevin Bosner. http://computer.howstuffworks.com/holographic-memory1.htm Optware Corporation of America, Longmont, Colorado, http://www.thic.org/pdf/Jul05/opt ware.mdeese.050719.pdf Technology Review, July
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