Abstract

We describe a new method of increasing the density of information stored on optical storage disks. This technology is based on the use of distinct data layers which are partially transmissive and separated by a spacer layer¹. It takes advantage of the narrow depth of focus provided by the objective lens to allow selective access to data on each layer by moving the focal position of the objective lens. This technology is extendible to more than two layers, can be used with other methods of increasing storage capacity, and can be implemented with only modest changes to existing media and drive manufacturing lines.

© 1994 Optical Society of America