The invention optical device comprising a self-processing photopolymer material configured to produce a variable two- or three- dimensional diffraction pattern when said material is illuminated by a light source. The invention provides a new material science and process technology which produces a serialisable anti-counterfeit optical device, based on a self-processing photopolymer.

A method for determining the validity of a parallax image including receiving a captured two-dimensional image of a parallax image having at least three target identifiers, where at least two target identifiers are located at different depth planes in the parallax image; identifying the at least three target identifiers in the captured two-dimensional image of the parallax image and determining the spatial relationship between the at least three target identifiers in the two-dimensional image of the parallax image; comparing the spatial relationship of the at least three target identifiers in the captured two-dimensional image of the parallax image against a predetermined spatial relationship of the at least three target identifiers that indicates authenticity; and adjudicating the authenticity of the parallax image based on the degree of difference between the spatial relationship of the at least three target identifiers in the captured two-dimensional image and the predetermined spatial relationship.

A method for determining the validity of a parallax image including receiving a captured two-dimensional image of a parallax image having at least three target identifiers, where at least two target identifiers are located at different depth planes in the parallax image; identifying the at least three target identifiers in the captured two-dimensional image of the parallax image and determining the spatial relationship between the at least three target identifiers in the two-dimensional image of the parallax image; comparing the spatial relationship of the at least three target identifiers in the captured two-dimensional image of the parallax image against a predetermined spatial relationship of the at least three target identifiers that indicates authenticity; and adjudicating the authenticity of the parallax image based on the degree of difference between the spatial relationship of the at least three target identifiers in the captured two-dimensional image and the predetermined spatial relationship.

Systems, devices, and methods for holographic optical elements are described. A holographic optical element includes a first layer of holographic material and a second layer of holographic material. The first layer of holographic material includes a first hologram responsive to light in a first waveband and a second hologram responsive to light in a second waveband. The second layer of holographic material includes a third hologram responsive to light in a third waveband and may include a fourth hologram responsive to light in a fourth waveband. The first, second, third, and fourth wavebands are distinct and may comprise light of red, blue, green, and infrared wavelengths, respectively. Distribution of the three or four holograms on two layers of holographic material allows each hologram to have an index modulation of greater than 0.016, a diffraction efficiency of greater than 15%, and an angular bandwidth of greater than 12.

A digital holography device of an embodiment of the present invention includes: an image sensing device which records, in an image sensor and on the basis of an object, a plurality of holograms that correspond to respective different photographic exposure values; and a computer which (i) generates a high dynamic range hologram, which includes pieces of information ranging from low luminance information to high luminance information, by synthesizing the plurality of holograms recorded and (ii) generates a reconstructed image of the object by performing arithmetic processing of phase-shift interferometry, diffraction calculation, and/or the like on the basis of the high dynamic range hologram.

A description is given of a document with a hologram as a security feature, in particular an identity card (12), consisting of a polycarbonate card body (10), which has a volume hologram label (2, 9) embedded therein. A description is additionally given of a method for producing the document, in which volume hologram labels (2) arranged on a carrier sheet are brought into contact with adhesive regions (4) on a thermoplastic sheet (5.1), the adhesive surfaces are cured and the carrier sheet is then removed. A second plastics sheet (5.2) is then adhesively bonded onto the first plastics sheet (5.1), bearing the hologram labels, using a second adhesive (7) in the region of the hologram labels (2) to form a two-layered sheet composite (6) which, finally, is laminated, together with further thermoplastic sheets, in a card-lamination press, under the action of pressure and temperature, to give a card body (10), individual identity cards (12) being punched out.

A description is given of a document with a hologram as a security feature, in particular an identity card (12), consisting of a polycarbonate card body (10), which has a volume hologram label (2, 9) embedded therein. A description is additionally given of a method for producing the document, in which volume hologram labels (2) arranged on a carrier sheet are brought into contact with adhesive regions (4) on a thermoplastic sheet (5.1), the adhesive surfaces are cured and the carrier sheet is then removed. A second plastics sheet (5.2) is then adhesively bonded onto the first plastics sheet (5.1), bearing the hologram labels, using a second adhesive (7) in the region of the hologram labels (2) to form a two-layered sheet composite (6) which, finally, is laminated, together with further thermoplastic sheets, in a card-lamination press, under the action of pressure and temperature, to give a card body (10), individual identity cards (12) being punched out.

The objective of the present invention is providing a method for fabricating high quality diffractive waveplates and their arrays that exhibit high diffraction efficiency over large area, the method being capable of inexpensive large volume production. The method uses a polarization converter for converting the polarization of generally non-monochromatic and partially coherent input light beam into a pattern of periodic spatial modulation at the output of said polarization converter. A substrate carrying a photoalignment layer is exposed to said polarization modulation pattern and is coated subsequently with a liquid crystalline material. The high quality diffractive waveplates of the present invention are obtained when the exposure time of said photoalignment layer exceeds by generally an order of magnitude the time period that would be sufficient for producing homogeneous orientation of liquid crystalline materials brought in contact with said photoalignment layer. Compared to holographic techniques, the method is robust with respect to mechanical noises, ambient conditions, and allows inexpensive production via printing while also allowing to double the spatial frequency of optical axis modulation of diffractive waveplates.

When coating a document surface (3) having relief-like information (1) carrying personal data, for example, with a monomer-containing liquid UV adhesive (4) across the entire surface and then laminating thereon a volume hologram (2), the varying adhesive thicknesses between the volume hologram and the document surface resulting from the relief cause differentiated swelling and thereby a differentiated color shift of the hologram. After the desired color shift is achieved, the UV adhesive (4) is completely cured. In this way, individual holographic information is obtained, which is located exactly above the relief-like information of the document. With this method, holographic overlays comprising personal data and a passport picture can be produced, and it is possible to link defined optical document information to the hologram in an accurately positioned manner, so that information is visible both non-diffractively and, from a different viewing angle, holographically in a different color.

When coating a document surface (3) having relief-like information (1) carrying personal data, for example, with a monomer-containing liquid UV adhesive (4) across the entire surface and then laminating thereon a volume hologram (2), the varying adhesive thicknesses between the volume hologram and the document surface resulting from the relief cause differentiated swelling and thereby a differentiated color shift of the hologram. After the desired color shift is achieved, the UV adhesive (4) is completely cured. In this way, individual holographic information is obtained, which is located exactly above the relief-like information of the document. With this method, holographic overlays comprising personal data and a passport picture can be produced, and it is possible to link defined optical document information to the hologram in an accurately positioned manner, so that information is visible both non-diffractively and, from a different viewing angle, holographically in a different color.