Pushing the limits of optical storage

Philips Research has been working on improvements of optical disc storage technology for three decades. In this period, optical discs have become the technology of choice for storing and sharing of data on removable media. In 30 years we have made an improvement of about 2 orders of magnitude in both data rate and storage density. The new Blu-ray Disc (BD) optical storage system offers 25 GB on a single layer, with 36 Mbps base data rate. Philips has made an optical pick-up unit with a single lens and a single detector that can be used for BD as well as for DVD and CD. We doubled the BD-storage capacity and increased the data rate by another order of magnitude in our two-dimensional optical storage format TwoDOS. Furthermore, we are exploring near-field optical storage for capacities beyond Blu-ray Disc. By using a solid immersion lens in a conventional actuator, we have realized an experimental laboratory system with remarkable robustness. We have found that near-field optical storage may be used on discs that have a cover layer to protect the data from scratches.