Holographic Versatile Disc

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This article contains information about a scheduled or expected future product. It may contain preliminary or speculative information, and may not reflect the final version of the product.

Picture of a HVD by Optware.

Holographic Versatile Disc (HVD) is an optical disc technology still in the research stage which would hold up to 3.9 terabytes (TB) of information. It employs a technique known as collinear holography, whereby two lasers, one red and one blue-green, are collimated in a single beam. The blue-green laser reads data encoded as laser interference fringes from a holographic layer near the top of the disc while the red laser is used as the reference beam and to read servo information from a regular CD-style aluminium layer near the bottom. Servo information is used to monitor the position of the read head over the disc, similar to the head, track, and sector information on a conventional hard disk drive. On a CD or DVD this servo information is interspersed amongst the data.

A dichroic mirror layer between the holographic data and the servo data reflects the blue-green laser while letting the red laser pass through. This prevents interference from refraction of the blue-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[2]. These discs have the capacity to hold up to 3.9 terabytes (TB) of information, which is approximately 6,000 times the capacity of a CD-ROM, 830 times the capacity of a DVD, 160 times the capacity of single-layer Blu-ray Discs, and about 8 times the capacity of standard computer hard drives as of 2007. The HVD also has a transfer rate of 1 gigabit/s. Optware was expected to release a 200 GB disc in early June 2006, and Maxell in September 2006 with a capacity of 300 GB and transfer rate of 20 MB/s [3] [4]. Since the announcement, there have been no further news or products on market.

The standards body Ecma International is leading the standard setting group for HVD, and expects to submit a proposed standard to the International Organization for Standardization for ISO approval, around December 2006. [5]

Holographic Versatile Disc structure
1. Green writing/reading laser (532 nm)
2. Red positioning/addressing laser (650 nm)
3. Hologram (data)
4. Polycarbon layer
5. Photopolymeric layer (data-containing layer)
6. Distance layers
7. Dichroic layer (reflecting green light)
8. Aluminium reflective layer (reflecting red light)
9. Transparent base
P. PIT

[edit] Technology

Current optical storage saves one bit per pulse, and the HVD alliance hopes to improve this efficiency with capabilities of around 60,000 bits per pulse in an inverted, truncated cone shape that has a 200 micrometer diameter at the bottom and a 500 micrometer diameter at the top. High densities are possible by moving these closer on the tracks: 100 GB at 18 micrometers separation, 200 GB at 13 micrometers, 500 GB at 8 micrometers and a demonstrated maximum of 3.9 TB for 3 micrometer separation on a 12 cm disc.

The system uses green laser, with an output power of 1 watt, a high power for a consumer device laser. So a major challenge of the project for widespread consumer markets is to either improve the sensitivity of the polymer used, or develop and commoditize a laser capable of higher power output and suitable for a consumer unit.^[1]

[edit] Storage capacity in context

Holographic Versatile Card, a variation of the Holographic Versatile Disc

It has been estimated that the books in the U.S. Library of Congress, one of the largest libraries in the world, would contain a total of about 20 terabytes if scanned in text format (4,000 terabytes, or 4 petabytes, if converted into Microsoft Word format). Not including images from the books, the content could be stored with capacity to spare on six 3.9 TB discs.

At 15 meter resolution and 32-bit color (about the resolution found in unpopulated areas on Google Earth), a map of the land masses of Earth would occupy just over 2 TB. Using MPEG4 ASP encoding, a 3.9 TB HVD could hold between 4,600–11,900 hours of video—just over one year of uninterrupted video at usual encoding rates.^[2] Using typical satellite radio encoding (CT-aacPlus at 40 kbps), a 3.9 TB HVD could hold over 26.5 years of uninterrupted stereo audio.

The transfer rate is at an average of 1 gigabit/second, or 1024 megabits/second, around 6 times the transfer rate for current 16x DVD storage. ^[3]

[edit] Competing technologies

HVD is not the only technology in next-generation, high-capacity optical storage media. InPhase Technologies has developed a holographic format they call Tapestry Media, capable of storing up to 1.6TB with a data transfer rate of 120 MB/s (960 Mbit). Hitachi Maxell, Ltd. plans to enter the market by offering 300 GB discs with a data transfer rate of 20 MB/s (160 Mbit). Such large optical storage capacities compete favorably with both HD DVD and Blu-Ray Disc. However, the reader will cost around US$15,000, and a single disc will cost around US$120-180, but prices are expected to fall steadily. [6]. The market for this format is not initially the common consumer, but enterprises with very large storage needs.

[edit] The HVD Alliance

The HVD Alliance is a coalition of corporations purposed to provide an industry forum for testing and technical discussion of all aspects of HVD design and manufacturing. By cooperating, members of the Alliance hope to expedite development and engender a market receptive to HVD technology.

As of February 2006, the HVD Alliance comprises these corporations:

• Alps Electric Corporation, Ltd.
• CMC Magnetics Corporation
• Dainippon Ink and Chemicals, Inc. (DIC)
• EMTEC International (subsidiary of the MPO Group)
• Fuji Photo Film Company, Ltd.
• Konica Minolta Holdings, Inc.
• LiteOn Technology Corporation
• Mitsubishi Kagaku Media Company, Ltd. (MKM)
• Nippon Kayaku Co., Ltd.
• Nippon Paint Company, Ltd.
• Optware Corporation
• Pulstec Industrial Company, Ltd.
• Shibaura Mechatronics Corporation
• Software Architects, Inc. (?)
• Suruga Seiki Company, Ltd.
• Targray Technology International, Inc.
• Teijin Chemicals, Ltd.
• Toagosei Company, Ltd.
• Tokiwa Optical Corporation

[edit] Proposed standards

Ecma, along with the TC44 committee, will work on standards for 200 GB holographic versatile disk (HVD) cartridges, 100 GB HVD read-only disks, 30 GB HVD cards and an optional provision for HVD-ROM disks. [7]

[edit] References

1. ^ http://www.eetimes.com/news/latest/sh
2. ^ Common compression rates for personal storage vary between around 780 and 2000 kbit/s. 3.9 TB equals 2000 kbit/s times 4,650 hours, or 780 kbit/s times 11,930 hours.
3. ^ "Holographic recording technology records data on discs in the form of laser interference fringes, enabling existing discs the same size as today's DVDs to store as much as one terabyte of data (200 times the capacity of a single layer DVD), with a transfer speed of one gigabyte per second (40 times the speed of DVD). This approach is rapidly gaining attention as a high-capacity, high-speed data storage technology for the age of broadband." [1]

[edit] See also

• DVD
• HD DVD (HDDVD)
• Blu-ray Disc (BD)
• Ultra Density Optical (UDO)
• Professional Disc for DATA (PDD or ProDATA)
• Holographic memory
• Tapestry Media
• Protein-coated disc
• Magneto-optical drive (MO)
• Holographic Versatile Card
• SVOD (Stacked Volumetric Optical Disk)
• InPhase Technologies - developer of competing holographic disc

[edit] External links

• DaTARIUS signs agreement with InPhase Technologies to be their sole sales, service and support supplier of HVD hardware and media to ship starting in 2007 (300GB WORM discs) with 600GB discs and re-writable technology in 2008 as well as 1.6TB media available in 2010.
• HVD Alliance HVD standards group.
• Optware Creator of HVD format.
• inphase-technologies.com a company developing a competing holographic storage format (*See Above).
• [8] PC Magazine, October 4, 2006 movie concerning holographic storage
• Holography system rides single beam EE Times,27 February 2006 - Interview with Hideyoshi Horimai and Yoshio Aoki of Optware Corp.
• Holographic storage standards eyed EE Times,28 February 2006 - article about the upcoming technical committee meeting to begin standardization of HVD.
• How stuff works explains how HVD works