Abstract: Photosensitive polyimides (Ps-PIM) materials have been synthesized that belong to three families of Ps-PIM materials. Through the use of precursors, various catalytic compositions with differing photosensitivities are provided. The results are Ps-PIM materials having increased photosensitivities at wavelengths longer than approximately 330 to 350 nm and an associated catalytic system that is insensitive to oxygen. A variety of applications, including use in holographic systems, are improved by the present invention.

Abstract: Novel photosensitive polymer films are provided that include (1) a polymer carrier having .dbd.N--C(.dbd.O)-- groups; (2) an initiation system for photo polymerization; (3) polymerizable compounds; and (4) other chemicals as appropriate. The photosensitive polymer films demonstrate short pump times, short DRAW times, short fix times, and reduced noise levels equal to one-third to one-fifth the noise level of prior photosensitive polymer films.

Abstract: A holographic storage system and method are provided in which a light source (12) is used to generate a coherent light beam which is split into a reference beam (18) and an object beam (20). The reference beam (18) is directed to the holographic storage medium (22) through use of a reference beam multiplexer (24). The object beam is encoded with a pattern encoder (34) and directed to the holographic storage medium (26). During read out, the object beam is reconstructed and detected by an optical detector (40).

Abstract: A method and apparatus for holographic storage with combined orthogonal phase codes and random phase codes are provided in which a reference beam (18) is encoded with a combination orthogonal phase code and random phase code by a phase encoder (28). A data pattern is imposed on an object beam (20) by pattern encoder (38). Both the reference beam (18) and the object beam (20) are directed to a particular stack site on a storage medium (32).

Abstract: An apparatus for positioning a data and reference beam onto the surface of a holographic storage media (10) includes a laser (16) for generating the reference beam, and a first reflecting surface (18) for positioning the output of the laser (16) along the y-axis. The beam is split into a data beam and a reference beam by a beam splitter (24) with the data beam directed toward an SLM (36) and the reference beam (26) directed toward an angle multiplexing reflective surface (40). The data beam during a record operation is reflected from the surface of the SLM (36) to a transform lens (34) and then to a column (35) on the surface of a holographic storage media (10). The reference beam is reflected from a reflective surface (40) at a predetermined angle determined by the position of the reflective surface (40) to an HOE (46) for redirection to the surface of the storage media (10) to interfere with the data beam. During a data reconstruction operation, only the reference beam is generated.