The disclosure relates to an optical waveguide for a display device and to a method for producing such an optical waveguide. The optical waveguide has a substrate on which a hologram layer is arranged. A cover layer includes a light-transmissive material that has been subjected to a curing process is arranged on the hologram layer. The substrate can consist of glass. Alternatively, the substrate likewise consists of a light-transmissive material that has been subjected to a curing process.

A method for integrating a hologram into the body of a security document that has a laminated body. The method includes: providing a holographic film having a backing substrate layer and a photo layer; providing additional substrate layers; carrying out a laminating process in order to form the laminated body, the holographic film together with the additional substrate layers being collated to form a substrate layer stack and being combined, together with the additional substrate layers, in a high-pressure, high-temperature laminating method to form the laminated body. There is also described a corresponding security document body.

The present invention relates to surface functionalized titanium dioxide nanoparticles, a method for its production, a coating composition, comprising the surface functionalized titanium dioxide nanoparticles and the use of the coating composition for coating holo-grams, wave guides and solar panels. Holograms are bright and visible from any angle, when printed with the coating composition, comprising the surface functionalized tita-nium dioxide nanoparticles.

Disclosed herein is a method for forming a surface relief microstructure, including the steps of A) applying a curable composition to at least a portion of the frontside of the paper substrate, B) contacting at least a portion of the curable composition with surface relief microstructure, C) curing the composition by using at least one UV lamp which is arranged on the backside of the paper substrate, and D) depositing a metallic layer, and optionally a layer of a transparent high refractive index material, on at least a portion of the cured composition, wherein the UV lamp has an emission peak in a UV-A range of 320 nm to 400 nm and additionally in a near VIS range of 400 nm to 450 nm, the curable composition comprises a photoinitiator which absorbs in the UV-A range and also in the near VIS range.

Various embodiments of the present technology generally relate to reflection suppressors. More specifically, some embodiments use elastomeric materials doped with optical absorbers for temporary suppression of Fresnel reflections for multiple substrates spanning wide spectral and angular bandwidth. The refractive index of the elastomer can be tuned to match a substrate and thereby minimize reflection. Some embodiments can use the addition of different absorptive dopants to allow for either broadband or wavelength-selective reflection suppression. As performance is limited only by index mismatch, both spectral and angular performance significantly exceed that of anti-reflection coatings. After use, these light traps may be removed and reused without damaging the substrate. These films have uses in spectroscopic ellipsometry, holography, and lithography.

Disclosed herein is a method for forming a surface relief microstructure, including the steps of A) applying a curable composition to at least a portion of the frontside of the paper substrate, B) contacting at least a portion of the curable composition with surface relief microstructure, C) curing the composition by using at least one UV lamp which is arranged on the backside of the paper substrate, and D) depositing a metallic layer, and optionally a layer of a transparent high refractive index material, on at least a portion of the cured composition, wherein the UV lamp has an emission peak in a UV-A range of 320 nm to 400 nm and additionally in a near VIS range of 400 nm to 450 nm, the curable composition comprises a photoinitiator which absorbs in the UV-A range and also in the near VIS range.

A method and an apparatus for forming a surface relief microstructure, especially an optically variable image on a paper substrate are provided, the method comprising the steps of: A) applying a curable composition to at least a portion of the frontside of the paper substrate; B) contacting at least a portion of the curable composition with surface relief microstructure, especially optically variable image forming means; C) curing the composition by using at least one UV lamp (1, 2, 3) which is arranged on the backside of the paper substrate; D) optionally depositing a layer of a transparent high refractive index material and/or a metallic layer on at least a portion of the cured composition, wherein the lamp (1, 2, 3) having emission peak(s) in the UV-A and near VIS range and the curable composition comprises at least a photoinitiator which absorbs in the UV-A region and preferably in the near VIS range. A paper product obtainable uses the method and an apparatus for forming a surface relief microstructure on a paper substrate. Surface relief microstructures, such as holograms may be replicated rapidly and with accuracy on a paper substrate by using the method and the apparatus.

A method of manufacturing a holographic pattern-expressing organogel, by using a dithering mask, according to an aspect of the present disclosure includes: preparing a dithering mask including white pixels and black pixels arranged in periodic patterns; photocuring a polymer by passing an ultraviolet ray through the dithering mask; passing a first solvent through the cured polymer; and passing a second solvent through the cured polymer through which the first solvent is passed.

A method for integrating a hologram into the body of a security document that has a laminated body. The method includes: providing a holographic film having a backing substrate layer and a photo layer; providing additional substrate layers; carrying out a laminating process in order to form the laminated body, the holographic film together with the additional substrate layers being collated to form a substrate layer stack and being combined, together with the additional substrate layers, in a high-pressure, high-temperature laminating method to form the laminated body. There is also described a corresponding security document body.

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.