In a first aspect, a multilayer film includes a holographic image layer, a first heat-shrinkable layer and a first adhesive layer between the holographic image layer and the first heat-shrinkable layer. In a second aspect, an authentication label includes a holographic image layer, a first heat-shrinkable layer, a first adhesive layer between the holographic image layer and the first heat-shrinkable layer, and a back adhesive layer.

The invention relates to a multilayer body with a volume hologram layer and a partial opaque layer, arranged on a surface of the volume hologram layer, which is present in a first area and is not present in a second area. The invention furthermore relates to a method for the production of such a multilayer body, as well as a security element and security document with such a multilayer body.

The present invention relates to layer composites comprising at least one opaque layer a) and at least one transparent layer b), wherein the Vicat softening temperature B/120 determined according to ISO 306:2004 (method B120 50N; 120° C.) of layer a) is ≥156° C., preferably from ≥156° C. to ≤250° C., particularly preferably from ≥156° C. to ≤230° C., and wherein the Vicat softening temperature B/120 determined according to ISO 306:2004 (method B120 50N; 120° C./h), of layer a) is higher than that of layer b), a method for producing such layer composites and security documents, preferably identification documents, comprising such a layer structure.

An optical system includes a substrate and a polarization volume hologram (PVH) composite film formed over the substrate. The PVH composite film includes a first PVH layer formed over the substrate and having a helix twist of a first handedness, and a second PVH layer coupled to the first PVH layer and having a helix twist of a second handedness orthogonal to the first handedness. The first PVH layer is configured to reflect and converge circularly polarized light having the first handedness. The second PVH layer is configured to reflect and converge circularly polarized light having the second handedness.

An optical system includes an optical lens, a polarization volume hologram (PVH) layer arranged over the optical lens, and an IR absorbing structure arranged between the optical lens and the PVH layer. The PVH layer being configured to reflect infrared (IR) light. The IR absorbing structure includes a quarter-wave plate (QWP) arranged between the optical lens and the PVH layer and a linear absorptive polarizer arranged between the QWP and the optical lens. The linear absorptive polarizer is configured to absorb IR light.

An interlayer film (10) for laminated glass comprises an optical function layer (15) and a first thermoplastic resin layer (11) provided on one surface (15A) side of the optical function layer (15). The optical function layer (15) comprises a matrix polymer, a polymer of a photoreactive monomer, and a photopolymerization initiator. The first thermoplastic resin layer (11) comprises an ultraviolet ray absorber and has a transmittance at a wavelength of 400 nm of 20% or less.

A method for making an optical grating having a non-uniform refractive index profile along a direction substantially perpendicular to a plane defined by the optical grating includes placing a layer of photopolymerization material having a first surface and a second surface that is opposite to the first surface between a first material transfer layer and a second material transfer layer so that the first surface of the layer of photopolymerization material is in contact with the first material transfer layer and the second surface of the layer of photopolymerization material is in contact with the second material transfer layer to allow material transfer between the layer of photopolymerization material and the first and second material transfer layers by diffusion.

Techniques disclosed herein relate to modifying refractive index modulation in a holographic optical element, such as a holographic grating. According to certain embodiments, a holographic optical element or apodized grating includes a polymer layer comprising a first region characterized by a first refractive index and a second region characterized by a second refractive index. The holographic optical element or apodized grating includes a plurality of nanoparticles dispersed in the polymer layer. The nanoparticles have a higher concentration in either the first region or the second region. In some embodiments, the nanoparticles may be configured to increase the refractive index modulation. In some embodiments, the nanoparticles may be configured to apodize the grating by decreasing the refractive index modulation proximate to sides of the grating. The refractive index may be modulated by applying a monomer reservoir buffer layer to the polymer layer, either before or after hologram fabrication.

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.

A replication tool for use in preparing a holographic film by replication, comprising a base structure having a structure body and a channel configured to receive at least one of a laminated glazing and a master holographic film assembly.