Optical recording method and apparatus utilizing polymeric birefringent materials

Abstract

An optical recording media as well as methods and apparatus for reading and writing on the novel media are provided. The novel media has the property of birefringence, and information is stored thereon by modifying the birefringence of the storage media at selected locations and leaving the birefringence of the storage media intact at other selected locations. Alternatively, information is stored by inducing birefringence onto the storage media only at selected locations. The information may be stored either in a binary format, or in a multi-level (or analog) format. In a birefringent material wherein birefringence is formed by stretching, a pulse from a focused laser is utilized to modify the birefringence at selected locations by the application of thermal energy. The recorded information is read by passing polarized light through the material and ascertaining whether the polarized light was modulated as it passed through the various selected locations. It is possible to read with the same laser used for writing by decreasing the power during the read step. Alternatively, various methods are described for rendering the media incapable of further recording of information.

Dependencies are inferred from the claim text.