An optical information recording/reproducing device which records an interference pattern between a reference beam and a signal beam as a hologram in an optical information storage medium or reproduces information from the optical information storage medium, the optical information recording/reproducing device includes a light source unit which emits a light beam, a signal-beam/reference-beam optical unit which generates the signal beam and the reference beam from the light beam and irradiates the optical information storage medium, a spatial light modulator which adds information to the generated signal beam, a photodetection unit which detects a reproduced beam from the optical information storage medium and acquires a reproduced image constituted by a plurality of pixels arrayed in a lattice shape, and a signal processing unit which performs equalization processing to a first pixel of the reproduced image to have a target characteristic.

Disclosed are various methods for creating optical elements through holographic fabrication. One method includes positioning a reflector in an optical path, disposing a first substrate proximal to the reflector along the optical path, disposing a first photosensitive film on the side of the first substrate facing the reflector, transmitting a light beam at a first polarization from a light source along the optical path, reflecting the light beam off the reflector, wherein the reflected light beam has a second polarization, receiving the reflected light beam through the first film and the first substrate, and applying a liquid crystal layer to the first photosensitive film to reproduce the alignment pattern of the first film on the liquid crystal layer.

We describe methods of mass-producing full color, 3D holograms, potentially incorporating a personalized image, which are particularly suitable for security purposes. Broadly speaking in embodiments a method generates, electronically, an interlaced image comprising a set of different views of a 3D object from different angles. This is projected onto a diffusing screen using coherent light and mapped from the screen into an angularly encoded object beam using a lenticular array. The different views in the angularly encoded object beam are then recorded simultaneously into holographic film using a reference beam.

An optical information recording/reproducing device which records an interference pattern between a reference beam and a signal beam as a hologram in an optical information storage medium or reproduces information from the optical information storage medium, the optical information recording/reproducing device includes a light source unit which emits a light beam, a signal-beam/reference-beam optical unit which generates the signal beam and the reference beam from the light beam and irradiates the optical information storage medium, a spatial light modulator which adds information to the generated signal beam, a photodetection unit which detects a reproduced beam from the optical information storage medium and acquires a reproduced image constituted by a plurality of pixels arrayed in a lattice shape, and a signal processing unit which performs equalization processing to a first pixel of the reproduced image to have a target characteristic.

A surface relief structure includes a recording medium configured to be structurally modified when exposed to interfering and non-interfering portions of radiation beams, the structurally modified recording medium including, when viewed in a two-dimensional cross-section along one of the axes of the recording medium a plurality of equally spaced steps of fine-sized periodicity superimposed upon a plurality of deep depressions of substantially coarse-sized periodicity. The structurally modified recording medium is configured to produce in reflection single and multiple colors in a broad spectral range when illuminated by a source of light.

A photorefractive (PR) polymer composite (310) is provided that includes a charge transporting polymer (CTP) matrix (311) and a photosensitizer (312) comprising a quantum dot (QD) material (314) with a first band gap (315) coupled to a nanoparticle material (317) with a second band gap (316) greater than the first band gap. The photosensitizer (312) is configured to generate a plurality of free charges (318) and to transfer the free charges to the CTP matrix (311) in response to an incident photon (320) on the PR polymer composite (310). An apparatus (500) is also provided, for writing holograms of 3D perspective views of an object from different directions within the PR polymer composite (310). A method (600) is also provided for forming the PR polymer composite.

Hybrid white-light viewable holograms and methods for making them. The holograms are hybrid reflection holograms made using the diffractive structures or gratings of a holographic object such as a transmission hologram or holographic optical element (HOE). The wavefronts of the diffractive structures are converted into a reflection hologram by scanning them with a coherent light source having a profiled narrow beam. The hybrid reflection hologram can exhibit display parameters including the multiple colors, solidity, and color stability of white light reflection holograms, the diffractive color shifting of a white light transmission hologram, three dimensional imaging and a wide variety of dynamic changes. Different areas or images with each of these effects can be combined in a single hologram. These hybrid reflection holograms are ideal for security and forgery prevention applications.