Increasing the Storage Density for a 4th-Generation Optical Disc

While CD, D VD and Blu-ray Disc (BD) are on the market, attempts are being made by industry and research facilities to further increase the storage density for the next or 4th generation of optical storage. The objective is an increase by a factor of 3 ... 4 compared to BD. The European funded project MobileDrive/4GOOD (4th-Generation, Omni-purpose Optical Disc-system) chose the Super-Resolution Near-Field Structure (SuperRENS) technology as the basis to decrease the minimum mark length as well as the track pitch on the disc. The contribution emphasises the steps taken in disc development and signal processing, and the results achieved so far. Disc development covers the layer stack of the disc and materials for the layers, especially comparison of different materials for the SuperRENS layer. Signal processing methods include clock recovery, bit detection, demodulation and inner and outer forward error correction.