Early experiments on optical disc storage

Optical technology was early proposed to attain information density higher than 10 Gb/in/sup 2/ with fast data transfer for storage of video, audio, or computer data either using holography or bit-by-bit memory architectures. We present how the concepts and technological issues have progressed at THOMSON-CSF and in other laboratories for the demonstration of an optical pickup enabling the readout of a 30-min TV program recorded as microtips on a spinning disc. The main technical breakthroughs are presented until first commercial success was achieved with the compact optical audio disc (CD) and evolution toward the optical CD-ROM and the DVD. Future research directions for achieving extremely high capacity in a compact system are also discussed.