Communications: Ten billion bits on a disk: High-power laser diodes and pregrooved disks enable low-cost digital data recording and retrieval

Compact, high-power laser diode systems should make optical-disk recorders attractive for general office use. Their price/performance ratio will make possible such devices as electronic filing cabinets for electronic mail. For these applications, they have advantages over recently announced optical-disk recorders that employ high-power gas lasers and external modulators. Such recorders of digital information are relatively bulky and expensive and are mainly applicable for mass-storage systems.