A method of forming a security device includes: a holographic image layer, diffusion element, and barrier layer. A region of the barrier layer includes a heat-transformable material. The method further includes selectively applying heat at a plurality of positions within the region of the barrier layer, in accordance with a predetermined pattern, so as to modify the heat-transformable material such that the region of the barrier layer is selectively rendered passable to the diffusible substance at each of the plurality of positions, thereby permitting diffusion of the diffusible substance between the regions of the diffusion element and the holographic image layer such that, at a plurality of positions within the region of the holographic image layer and corresponding to the predetermined pattern, the volume hologram is dimensionally modified so as to become viewable in a second observable colour, different from the first observable colour.

The invention relates to a scaled holographic medium comprising a layer construction B′-C1′-C2′, to a process for producing the sealed holographic medium, to a kit of parts, to a layer construction comprising a protective layer and a substrate layer and to the use thereof.

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.

The present disclosure relates in one aspect to methods of preparing non-homogeneous polymer materials wherein light is used to control structure and/or composition. In certain embodiments, the present disclosure provides methods for creating gradient index optical elements including holographic elements.

The present disclosure relates in one aspect to methods of preparing non-homogeneous polymer materials wherein light is used to control structure and/or composition. In certain embodiments, the present disclosure provides methods for creating gradient index optical elements including holographic elements.

The invention relates to a sealed holographic medium comprising a layer construction containing a photopolymer layer and a sealing layer, to a process for producing the sealed holographic medium, to a kit of parts, to a layer construction for sealing and to the use thereof.

The invention relates to a scaled holographic medium comprising a layer construction B-C1-C2, to a process for producing the sealed holographic medium, to a kit of parts, to a layer construction comprising a protective layer and a substrate layer and to the use thereof.

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 main object of the present invention is to provide a method of producing a volume hologram laminate which can regenerate a hologram image in an arbitrary wavelength by a simple process. To attain the object, the present invention provides a method of producing a volume hologram laminate using a volume hologram forming substrate which comprises: a substrate, a volume hologram layer formed on the substrate and containing a photopolymerizable material, a resin layer, formed on the substrate so as to contact to the volume hologram layer, containing a resin and a polymerizable compound, characterized in that the producing method comprises processes of: a hologram recording process to record a volume hologram to the volume hologram layer, a substance transit process of transiting the polymerizable compound to the volume hologram layer, and an after-treatment process of polymerizing the polymerizable compound.

Systems, devices, and methods for controlled hologram playback shifting are described. The playback of a hologram may be shifted to a longer wavelength by diffusing donor material into the hologram in a controlled manner. A hologram may include a set of fringes, holographic recording medium and donor material. An apparatus to controllable shift playback angle of a hologram can include a hologram film holder, donor film holder, one or more light sources, light sensor, and curing lamp. A method may include monitoring playback light until an amount of playback shift occurs, and in response fixing a piece of hologram film and physically de-coupling a donor film therefrom.