Holograms as Data Storage

Today many computers support different types of data storage, including different types of memories and removable disks. In particular, a major new innovation includes the idea of holographic data storage. Orlov wrote, "No fully automated digital holographic data storage system had been implemented" prior to 1994, which obviously marks the young age of holographic data storage (Orlov 2000). Holographic data storage simply refers to using holograms instead of traditional circular disks and memories to store data. Holograms bring forth many attributes, which to a certain extent make them far superior to current methods of data storage. The following breaks holography into three major concepts including defining and describing holography, capacity and holographic speed capabilities.

Defining holography

Holography relies on the use of lasers and reflective materials instead of magnetism as most of today's storage devices rely on. According to Lambertus, holographic storage stores information "inside a medium, not merely on its surface (similar to hard disk data storage)," (Lambertus 2000). Additionally, holograms comprise three-dimensional objects, whereas memories and circular disks have a more two-dimensional use to them. The methods for reading and writing holograms do not involve a read/write head, as a disk of today's world would use. More precisely, reading a hologram occurs with the use of a continuous laser beam, and writing involves a pulsed laser to shine on a hologram (Orlov 2000). Just imagine a cube composed of nothing more than light. The cube, or hologram, would naturally have length, width, and height, which comprise volume. Lasers, or beams of light, shine on the cube for reading and writing data.

Hologram Capacity

Holograms can store enormous amounts of data, which presents its most valuable feature as people have a great need for large amounts of space. Holograms consist of a "cube of light," as previously mentioned, however, one company in particular, Optware Corporation, has generated a hologram in the more conventional circular disk fashion (Yoshiko 2004). Their version of holographic data storage would allow for easy incorporation of the medium into existing computer systems and devices. When referring to magnetic data storage, Lambertus wrote, "Data storage capacity has increased at least 60% per year and more recently 80%-100% per year" (Lambertus 2000). Obviously the amount of data magnetic disks can store has vastly increased and continues to increase, however, holographic data storage has the potential to surpass magnetic disks' capacity immensely. Lambertus stated holographic storage could reach "Hundreds of gigabytes per disk" (Lambertus 2000). One article mentioned the fact holograms generated "noise," which can potentially corrupt data and limits the capacity of storage (Orlov 2000). Fortunately, Lambertus offered a solution to the problem by introducing a small mirror device, which would reduce the noise occurrence with holographic data storage. How the lasers, used with holograms, actually write data directly influences the overall capacity. In particular, Orlov mentioned a "differential encoding technique," which reduces the occurrence of errors when reading/writing data, thus increasing the capacity a hologram can support (Orlov 2000).

Hologram Speed

Another major issue includes the speed of holograms, or speed used in reading and writing data. Orlov wrote, "As many as a million bits can be read in parallel, compared to only one (or several) bits in conventional magnetic storage" (Orlov 2000). Additionally, Orlov mentioned a real prototype system developed, which successfully tested for an astonishing reading speed of one gigabyte per second. Holograms obviously present a huge advantage over magnetic storage devices of today's world. Additionally, "No mechanical motion is involved," which means holograms can reach high operating speeds because they only rely on laser beams (Williams 2003). Orlov estimates hologram read/write speeds range from 100 to 1,000 times faster than magnetic read/write speeds (Orlov 2000). Furthermore, smaller holograms require less read/write times than larger sizes, and because lasers require little energy, Williams argues the less energy used in reading/writing decreases the access times of data on a hologram (Williams 2003).

Conclusion

Holographic data storage devices will one day outnumber the existing hard disks and other magnetic based storage devices of today. Holographic data storage has great potential because of the various aforementioned properties of its amazing speed and capacity features. In particular, one article spoke of a prototype system, which used a hologram as data storage (Orlov 2000). The article mentioned several engineers successfully stored a video on a hologram, by using lasers to write the data and then lasers read the data from the hologram to play the video (Orlov 2000). Optware also successfully engineered its version of holographic data storage and projected the commercialization of holograms as data storage by the year 2007 (Yoshiko 2004). Orlov added, commercialization of holographic data storage "Depends mainly on the longevity of other storage technologies," and in particular Orlov gave DVD's as an example of a media, which requires large amounts of storage and quick access times (Orlov 2000). Furthermore, Orlov cautioned, "Holographic data storage will require a new and costly manufacturing infrastructure to produce competitively priced products in sufficient quantity and quality to satisfy the storage market, which already has many high-performance options" (Orlov 2000). New technologies generally start out quite expensive to consumers, however, with competition and consumer want, companies over time, generally reduce the costs for great technologies. Holograms as data storage have created a new field of interest for engineers, and will potentially become commonplace in the computer world.

References

Lambertus, Hesselink. "Ultra-high-density data storage: introduction". Stanford

Univ., Palo Alto, CA; and Siros Technologies, Inc., San Jose, CA. ACM Press New York, NY, USA. Volume 43, Issue 11, 2000. ISSN:0001-0782. 33-36.

Orlov, Sergei S. Stanford Univ., Stanford, CA. "Volume holographic data

storage". ACM Press New York, NY, USA Volume 43, Issue 11, November 2000 ISSN:0001-0782. 46-54.

Williams, John G. RCA Labs, Princeton, NJ. "Asymmetric Memory Hierarchies".

ACM Press New York, NY, USA. Volume 16, Issue 4, April 2003.

ISSN:0001-0782. 213-222. Yoshiko, Hara. "Sony spin-off prototypes Tbyte holographic storage -- Similar in

structure to legacy disks, optical medium could vie with HD-DVD, Blu-ray". Copyright 2004 CMP Media LLC Electronic Engineering Times August 30, 2004. 38.