Technology has moved at a mind numbing pace since optical disc technologies changed the way data is stored and distributed. Today Blu-ray disc is the capacity leader for optical disc storage. Current Blu-ray capacities are 25 GB on a single layer disc (BD-R), and 50 GB for double layer media (BD-R DL). Erasable discs (BD-RE) on which data can be written, erased, and new data written are also available.
The technology doesn’t stop here. The Blu-ray Disc Association recently announced a number of new, higher capacity formats:
BDXL: BDXL (we’ll probably think of this as Blu-ray Extra Large – but in a few years, with the potential for more advances, the idea of ‘extra large’ may seem rather quaint) discs can use as many as four 25 GB layers on a single disc, providing up to 100 B of storage. The Blu-ray Disc Association described a disc with the capacity of storing up to 128 GB.
The four (or five) layer disc will require a new type of recorder – current products can’t handle more than two layers. Additionally, with its high capacities, this disc will probably be used primarily for data storage (rather than as a medium onto which Blu-ray movies can be duplicated).
IB-HD: Intra-Hybrid Blu-ray Disc is a very interesting variation on the dual layer, 50 GB BD-R disc. Instead of providing the ability to record to both layers, or to erase both layers and re-record onto them in the case of erasable discs, the IB-HD disc provides one surface that is write-once, and a second surface that can be erased and re-written. It’s interesting to think about the variety of applications for this type of disc. Imagine, for example, an organization using this disc for running its computers. On one layer, the operating system (probably a Linux variant), applications and company specific data and settings are recorded. The other layer is used for storing the data produced by those applications. The user just puts the disc into the computer, boots from the data on the non-erasable layer, and the files created (and stored on the erasable layer) are unique to him or her. The potential for the hybrid disc is enormous.
GE also made an interesting optical disc storage announcement:
Holographic Storage: Holographs seem to have been the ‘next big storage breakthrough’ for decades. I wrote about breakthroughs by AT&T years ago. Now, GE’s Global Research Center has developed a process that will be capable of recording 500 GB of data onto a CD-sized disc. GE claims that data is recorded onto the disc in patterns – holograms – that have extremely high data densities.
The technologies used for holographic storage, according to GE, are similar enough to those used for other forms of optical storage that future holographic recorders/players will also be able to write and read ‘standard’ optical media. By the time we’ll be able to burn 100 GB BDXL discs on our office computers, the holographic discs may be ready for market.