IBM Corp, which licensed some of its blue laser technology to Coherenet Inc so that the company could make the devices for IBM and others, has been demonstrating a blue laser optical recording system that can read and write data at a density of 2.5G-bits per square inch, five times higher than current products using infra-red lasers, so that a typical double-sided 5.25 optical disk would hold 6.5Gb – the higher-frequency blue light can be focused to a smaller spot than can infra red light, so more data can be written in a given area – but the technology is a long way from being seen in disk drives.
