August 1, 2006 Holograms allow permanent optical data storage and retrieval with far higher densities than CDs or DVDs, using the interference patterns of two lasers. Physical chemists are now developing the technology into products based on optics that could store the equivalent of a movie on a thumb-sized hologram.
LONGMONT, Calif. -- The way we watch movies, television, listen to music, and store all kinds of data is changing. Soon it'll be possible to get everything you need or want saved on a disc no bigger than your thumb.
"So instead of having your movie on something the size of a standard disk, now you can talk about putting a movie on something maybe the size of a postage stamp -- if not smaller," Bill Wilson, chief scientist at InPhase Technologies in Longmont, Calif., tells DBIS.
Just think ... Your favorite movie or collection of songs stored on a single disc. Physical chemists say holograms are the holy grail of data storage.
Wilson says, "In many ways you can think of our disk as -- it's basically a library."
Two intersecting lasers store millions of bits of information on a disc. It's that intersection of those two beams that actually allows you to record the holographic data and later recover it.
It's the same concept as the images on credit cards we're all familiar with. Unlike the way information is stored on a CD, holographic storage stores information below the surface. And holographic storage promises to solve the movie industry's current "memory nightmare," thanks to optics. Right now all movies are stored on film because of its long shelf life. Even an epic like "Gone With the Wind," would take up only a tiny bit of holographic space.
"You know, Blockbuster could send out a disc with the top 50 movies of the month," Wilson says. The technology is here, now it's a question of how it will be used. "Well, that's a question for Warner Brothers."
InPhase Technologies and the Maxell company, known for VHS tapes, will start offering holographic storage systems for professionals late next year. The movie and broadcast industries will likely follow, but consumer products may take a while before they reach the marketplace.
BACKGROUND: Scientists have developed a holographic data storage system that promises to revolutionize the way we store data. Movie and broadcast companies will be among the first users because the technology is well suited for broadcasting and video editing: data is read and stored in parallel at a million bits at a time, and prototypes of holographic disk arrays have data transfer rates of 27 megabytes per second. Eventually consumers will be able to purchase high-definition videos, and have greater storage capacity in their cell phones and digital cameras.
HOW IT WORKS: While CDs and DVDs store information in single bits over the surface of the disk, holographic storage can store much more information faster (one million bits at a time) throughout the entire thickness of the disk. Holographic data storage would offer better copyright protection. DVDs and CDs can easily be copied by making an imprint of the "bumps" on the surface of the disk, but it's harder to this with holographic data storage because information is stored throughout the disks.
The key technology that makes this possible is the development of a material to make the disk that can support the way holograms are made. Earlier materials – most notably lithium niobate -- could be both recorded and read back, but in the process of reading back the data, the holograms were erased. Companies have been searching for the perfect recording material for 50 years. They haven't found it yet, but the emphasis has switched to polymeric materials onto which data can be recorded once, instead of being erasable.
ABOUT HOLOGRAMS: A hologram records the interference pattern made by two beams of light that interact with each other. One beam comes directly from the laser, while the other comes from the same laser but bounces off the object being imaged. Light waves behave just like water waves when they meet. Wherever a crest of one coincides with a crest of the other, an extra high crest will form, and where two troughs coincide, they will form an extra low trough. If a crest meets a trough, the two will cancel each other out. With light, the waves will form light (crests) and dark (troughs) fringes -- the telltale wave pattern that can be recorded on photographic film. After it is developed, the hologram is lit by a beam of light to recreate the 3D object in space.