Sony Corp. has announced development of a blue-laser based optical disc system for data storage and says it should be available by the end of this year. The system, which has yet to be named, is technically similar to the Blu-ray Disc format that was developed by a consortium of nine companies led by Sony, although it is incompatible. "It's for professional use and Blu-ray is for consumer use so there is no compatibility," said Aki Shimazu, a spokeswoman for Sony in Tokyo. She said that because the new system was not compatible with Blu-ray, Sony would not have to consult with other members of the consortium and it would have sole control over the system. The main difference between the two formats comes in the data transfer rate. Blu-ray, which is aimed at consumer recording of high-definition television, can record data onto the discs at a rate of up to 36M bps (bits per second) to match the data rate of digital television. However, Sony's new data storage system can record data at 9M bytes per second or double the rate of Blu-ray, said Sony in a statement. The first version of the format will be based around a single-sided, single-layer optical disc and will have a capacity of 23.3G bytes and rewritable and write-once versions will be available, said Sony. The disc is 12 centimeters, just like CDs or DVDs, and is encased in a cartridge to protect the media. Blue laser systems are able to store more data than DVDs because of the shorter wavelength of blue light. This means the laser, which is used to record data on the disc, makes a smaller spot on the recording layer and in turn that means that the space needed for each bit of data is smaller. Thus more data can be crammed onto the disc. The company's roadmap extends to a 50G byte capacity version by 2005 and a 100G byte capacity version at an unspecified point in the future and data transfer rates are expected to rise too. With the second generation disc they are predicted to double to 18M bytes per second and then double again, to 36M bytes per second, when the third generation version is launched. To support the fast data transfer, initial drives will have an Ultra-wide 160 SCSI interface, said Sony. Samples of the drive and media will be available from the middle of this year for around US$3,000 each for the drive and $45 for the media. The Tokyo company is aiming the new system squarely at the professional market, at least initially, and users of magneto optical disc systems and in this respect they are not alone. Plasmon said Monday it will offer drives for its new blue-laser based UDO (Ultra Density Optical) format that include legacy support for magneto optical devices. Targeted at the same market as Sony's new system, UDO is also similar to Blu-ray and based around cartridges that are dimensionally identical to current magneto optical cartridges. First generation UDO will support discs with a capacity of 30G bytes and a transfer rate of 8M bytes per second. Like Sony, Plasmon is also trying to sell the system based on future promises of higher capacity discs. Its roadmap extends to 60G byte and 120G byte discs.