Abstract: An apparatus for X-ray imaging is provided. An X-ray source provides an X-ray along an X-ray beam path. A holographic medium is along the X-ray beam path. An X-ray phase grating is between the X-ray source and the holographic medium along the X-ray beam path. A readout beam source provides a readout beam along a readout beam path. A readout detector is along the readout beam path, wherein the holographic medium is along the readout beam path.

Abstract: An optical storage system and method having separate, independent format hologram writing and data writing mechanisms to allow optimization of data writing separately from format hologram recording. In its most general terms, the invention comprises an optical medium having a first, photoactive material responsive to a first, format hologram recording condition, and a second photo-active material, responsive to a second data writing condition, which is dispersed or dissolved in the first photoactive material. The second photoactive material may additionally be “erasable” under a third, erasing condition. The second photoactive material is preferably in the form of microparticles, microdroplets or microcapsules which are dispersed throughout the first photoactive material.

Abstract: An optical storage system and method having separate, independent format hologram writing and data writing mechanisms to allow optimization of data writing separately from format hologram recording. In its most general terms, the invention comprises an optical medium having a first, photoactive material responsive to a first, format hologram recording condition and a second photo-active material, responsive to a second, data writing condition, which is dispersed or dissolved in the first photoactive material. The second photoactive material may additionally be “erasable” under a third, erasing condition. The second photoactive material is preferably in the form of microparticles, microdroplets or microcapsules which are dispersed throughout the first photoactive material.

Abstract: An optical data storage system and method comprising a photopolymer medium having generally a polymerizable monomer, an active binder, a first, hologram recording polymerization initiator, and a second, data writing polymerization initiator. The monomer is preferably a cationic ring-opening monomer. The hologram recording polymerization initiator preferably comprises a sensitizer and photoacid generator which initiate a first polymerization in the medium which defines a format hologram. The format hologram recording is carried out via interference of a signal and reference beam, with the sensitizer being specific for the wavelength(s) of the signal and reference beams. The hologram recording polymerization is only partial and does not consume all of the monomer present in the photopolymer medium.

Abstract: Rare earth doped ferroelectric materials are disclosed as reversible holographic recording medium (25) for use in two-photon recording systems. Such rare earth elements provide long-lived electronic states intermediate the ferroelectric material's valence and conduction bands. In some cases, these rare earth intermediate states have a sufficiently long life that low-power continuous wave ("cw") lasers (1) can be used to record interference patterns on them. Thus, two-photon holographic recording systems are also disclosed which do not require high-power, short pulse length, mode-locked or Q-switched lasers. Rather, the disclosed holographic recording systems employ cw lasers such as diode lasers. The rare earth dopants include praseodymium, neodymium, dysprosium, holmium, erbium, and thulium. These dopants provide ions having 4f excited states that give rise to absorptions in the near infra-red and visible spectral regions and typically have lifetimes on the order of 0.1 to 1 milliseconds.