Trends in storage of digital data.

Trends in the price and performance of several storage technologies are presented with emphasis on magnetic recording and semiconductor memories. Since these technologies present a moving target, new contenders cannot enter the marketplace unless they provide a significant advantage over the entrenched competition. It is concluded that in the next decade, optical storage of digital data can make an impact at the high capacity end-trillion bits and above-provided prices are at least an order of magnitude lower and access at least an order of magnitude faster than in present day systems.

Reactive optical information processing. I: theory of information recovery and resonator mode structure.

A method of processing optical information is described in which the use of absorptive spatial filters is replaced by suitable mirrors with spatially varying reflectances. When these mirrors are made the terminal planes of a laser resonator, the light which is lost in conventional spatial filtering systems, is stored in the laser cavity. It is shown that shallowly modulated phase objects may be imaged outside the resonator without any appreciable effect on the modes of the resonator.