Holographic Data Storage: Super Storage On Its Way

Store lot of data in a little bit of space. That is the promise of the new Holographic Data Storage (HDS) technology. InPhase Technologies has successfully demonstrated storage of 515 gigabits per square inch data density using this technology. And now it is poised to touch the 1.6 terabyte capacity.

A terabyte would be enough space to store hundreds of movies or a million books. Imagine all this data saved on to a one-square-inch space! US-based InPhase Technologies and Maxell Corporation have demonstrated this task through a revolutionary technology called Holographic Data Storage (HDS). At the National Association of Broadcasters 2005 (NAB) convention in Las Vegas, InPhase conducted the first public demonstration of the world's first prototype of a commercial storage device together with Maxell Corporation of America.

Holographic memory is a technology that uses a three dimensional medium to store data. It can access this data page at a time instead of sequentially, which leads to increase in storage density and access speed. It offers the possibility of storing one terabyte (TB) of data in a sugar-cube-sized crystal. Data from more than a 1,000 CDs could fit on a holographic memory system.

How it works?

Holographic recording technology utilizes intersecting signal and reference laser beams to store data in a number of 3D hologram images capable of saving hundreds of data pages in a single location. One five and 1/4 inch-diameter optical disc can store up to 150 million pages - more than 63 times the capacity of DVD. Also, with holographic recording, a multiple of form factors, such as discs, cards, etc and laser wavelengths (red, green, and blue) can be used.

"Combining high-storage densities and fast transfer rates with durable, reliable, low-cost media, holographic technology is poised to become a compelling choice for next-generation storage and content distribution needs," said Liz Murphy, VP-Marketing, InPhase Technologies. "Unlike other technologies that record one data bit at a time, holography allows a million bits of data to be written and read in parallel with a single flash of light. This enables transfer rates significantly higher than current optical storage devices," he added.

Both InPhase and Maxell claim holographic data storage to be superior to existing disc and hard drive technologies, and is also competitive against tape technologies in capacities and transfer rate. In addition, HDS offers a 50+ year media archive life and random data access. And most of all, the media is expected to have the lowest cost per gigabyte of any commercial quality removable storage.

InPhase demonstrated the highest data density of any commercial technology by recording 515 gigabits of data per square inch. According to the company, holographic storage is a revolutionary departure from all existing recording methods because it takes advantage of volumetric efficiencies rather than only recording on the surface of the material.

The first generation drive has a capacity of 300 gigabytes on a single disc with a 20 megabyte per second transfer rate. The first product will be followed by a family ranging from 800GB to 1.6 terabyte (TB) capacity. The first generation of holographic media with 300 GB of storage capacity and a 20 Mbps transfer rate is scheduled for release in late 2006.

Future impact

The impact that these data densities will have on future products is tremendous. For IT managers dealing with archiving millions of e-mail messages, higher densities mean savings on space, time, and power.

"Holographic media makes it possible for millions of pages of information and high definition images to be held on one small, relatively inexpensive disc," said Steven Pofcher, Senior Marketing Manager, Maxell.

"In April of 2005, we demonstrated 200GB per sq inch holographic data density and a year later the density has increased more than 2.5 times" Kevin Curtis CTO, InPhase

Surpassing expectations

Densities in holography are achieved by different factors than magnetic storage. Density depends on the number of pixels/bits in a page of data; the number of pages that are stored in a particular volumetric location; the dynamic range of the recording material; the thickness of the material, and the wavelength of the recording laser. "In April of 2005, we demonstrated 200GB per sq inch holographic data density and a year later the

density has increased more than 2.5 times," said Kevin Curtis, CTO, InPhase.

In the demonstration conducted by InPhase, there were over 1.3 million bits per data page, and 320 data pages spaced 0.067 degrees apart were stored in the same volume of material. A collection of data pages is referred to as a book, and InPhase's PolyTopic recording architecture enables more holograms to be stored in the same volume of material by overlapping not only pages, but also books.

HDS Sceptics

While the holographic memory and its potentials sound great, there are few who feel this technology in its present form may not be successful for the next many years. In one of the interviews found in the Internet, Bob Longman, Engineering Director, Plasmon, has expressed his doubts over the success of holographic technology for the next several years.

Plasmon is currently the largest blue laser storage media drive producer in the world and its 30GB capacity UDO optical drive is the market leader in professional optical archiving.

According to Longman, InPhase technology won't become a reliable and commercially affordable product for several years as it uses photosensitive media for holographic recording. That means the media has to be stored in a lightproof cartridge, unlike CD, DVD, UDO, Blu-ray and HD-DVD media. It also means that the drive has to be lightproof.

InPhase technology also requires the recording mechanism to be very precise. Which means any vibration and throw the light beam off-target. Longman also expresses concerns about the life of the light-source and its general interoperability of media and drives. Lastly, the commercially afforability of the drives and media will take a long time.

To overcome all this possibilities, Longman indicates that Plasmon may attempt at holographic storage technology with the Optware's collinear technology rather than InPhase's multi-angled approach. "The Optware technology conceivably has fewer technical hurdles to overcome," views Longman.

Conclusion

Despite all this doubt over the success of the technology, InPhase and Maxell are confident that their technology can provide long archival life with uncompressed storage capacities of 1.6 TeraBytes per disk and data rates as high as 120 Mbps.

If commercialized at an affordable rate, holographic storage will truly be a revolutionary achievement in optical storage space and a compelling choice for storage and archival requirements. The first products are likely to be expensive, and only feasible for large organizations with unusual needs for storage. However, vendors expect to make holographic storage available and affordable for the average consumer within the next few years.

Although current versions are not rewritable, the company expects to make holographic storage that can be rewritten within the next few years.

Nelson Johny

Source: DQ Channels