Abstract: A composition includes a siloxane of the formula: (RMe2SiO1/2)a(MeRSiO2/2)b(RSiO3/2)c(SiO4/2)d wherein a is at least 2, b is from 3 to 20, c is from 0 to 10, d is from 0 to 10, and each R is independently of the formula —CR?2—CR?2—Y—Z or CR?2—CR?2—Z, wherein each R? is independently a hydrogen atom or a C1 to C10 hydrocarbyl free of aliphatic unsaturation so long as at least one R? is a hydrogen atom, Y is a divalent organic group, and Z is a polycyclic group containing at least one aromatic ring. A method of making the siloxane includes charging (HMe2SiO1/2)a(MeHSiO2/2)b(HSiO3/2)c(SiO4/2)d, a platinum catalyst, and an alkene of the formula CR?2?CR?—Y—Z or CR?2?CR?—Z into a reactor to form the siloxane. The siloxane is useful as a component in holographic storage media for photopolymer-based holographic data storage applications. The siloxane exhibits excellent compatibility when mixed with a polymerizable component before the polymerizable component is cured.

Abstract: Disclosed is a holographic recording medium. The novel holographic recording mediums disclosed herein comprises: a) at least one polyfunctional epoxide monomer or oligomer which undergoes acid initiated cationic polymerization. Each epoxide in the monomer or oligomer is linked by group comprising a siloxane to a silicon atom and each monomer or oligomer has an epoxy equivalent weight of greater than about 300 grams/mole epoxide; b) a binder which is capable of supporting cationic polymerization; c) an acid generator capable of producing an acid upon exposure to actinic radiation; and optionally d) a sensitizer.

Abstract: Photosensitizing dyes are often used in conjunction with a photoacid generator in holographic recording media. Conventional photosensitizing dyes typically are limited by having an appreciable absorption of light when used in a sufficient concentration, such that the intensity of light decreases significantly with penetration into a recording medium. The present invention discloses a number of new 5-alkynyl substituted napthacene photosensitizing dyes that have low extinction coefficients coupled with good sensitizing properties, such that the problems associated with the photosensitizing dyes absorbing light are significantly reduced.

Abstract: Holographic data storage systems are fixed after exposure during which data in the form of holograms are stored at locations in the medium (4). Sufficient fixing energy in the form of light or other electromagnetic and thermal radiation is applied to the media (4) either by flooding the media, or to specific locations where the medium has been written. The energy is sufficient to expose the recorded medium (4) to prevent recording in the unused dynamic range thereof. Such recording can be a spurious recording made during readout or from spurious sources of light incident on the media. In one embodiment, the reference beam (108) produced in the course of holographic recording is redirected to locations on the media (4) which have already been recorded. The redirected beam post exposes the media to fix these locations against spurious recording. The integrity of the holographic data storage systems and the robustness thereof is improved by fixing methods and apparatus incorporating the invention.

Abstract: Holographic media for storing and reading holographic data is provided having one or more external or internal surfaces having structures for at least one of minimizing reflections from illumination incident the surface, or enhancing adhesion between surfaces within the media. Structures for minimizing reflections represent a grating pattern of subwavelength structures providing low reflectivity at the operating characteristics of holographic optical systems to use the media, such as spectral bandwidth, angular bandwidth, and polarization of illumination incident the media. Adhesion promotion may be provided by structures along an interior surface of the media, such as along an interfacing surface between photosensitive material of the media and a substrate material adjoining the photosensitive material. Such adhesion promotion may be provided by such structured surface with or without providing low reflectivity at the operating characteristics of holographic optical systems to use the media.