This proposal describes a three-dimensional bit-organized optical storage technology which can provide on-line millisecond access to 20,000 Gigabytes of data storage. The high data density and consequent short access time is accomplished by three-dimensional storage of an array of one-micron sized spots within a cubic photopolymer storage block measuring four inches to the side. Intersecting beams of visible laser light are used to write and also to read the data. Three-dimensional or volume storage is made possible by use of two-photon photochemistry activated only at the intersection point of two laser beams of different energy and intensity. The availability of a memory device with such large capacity and high speed will be important to all those concerned with the storage and retrieval of business, statistical, textual, or pictorial data. But the major impact of this technology will be industrial and economic, in an economy based upon automation and specialized computer arts such as artificial intelligence. The power of the three dimensional optical memory will also facilitate complex serial processing applications such as pattern recognition, weather forecasting, and image analysis. It also provides an ideal architecture for development of general purpose parallel processing.The potential commercial application as described by the awardee: This memory permits on-line access to libraries of business and textual material equivalent in size to thousands of optical disks. It also permits very sophisticated artificial intelligence programs to be performed.