The invention relates to a security element (1) with a first volume hologram layer (11), which spans a coordinate system with the coordinate axes x and y (3, 4) perpendicular to each other in an unbent state of the security element (1), wherein a first volume hologram is introduced into the first volume hologram layer (11) in at least one first area (51), wherein the first volume hologram is formed such that a first item of information (21-30) is visible for an observer (7) in a first observation situation in a first predefined bent state of the security element (1) and is not visible in the first observation situation in the unbent state of the security element (1) or vice versa.

An embodiment of the invention relates to a method for carrying out a time-resolved interferometric measurement comprising the steps of generating at least two coherent waves, overlapping said at least two coherent waves and producing an interference pattern, measuring the interference pattern for a given exposure time, thereby forming measured interference values, and analyzing the measured interference values and extracting amplitude and/or phase information from the measured interference values. In at least one time segment, hereinafter referred to as disturbed time segment, of the expo-sure time, the interference pattern is intentionally disturbed or destroyed such that the corresponding measured interference values describe a disturbed or destroyed interference pattern. In at least one other time segment, hereinafter referred to as undisturbed time segment, of the exposure time, the interference pattern is undisturbed or at least less disturbed compared to the disturbed time segment such that the corresponding measured interference values describe an undisturbed or less disturbed interference pattern. The measured interference values that were measured during the entire given exposure time, are filtered, wherein those interference values that were measured during the at least one disturbed time segment, are reduced, suppressed or discarded. The filtered interference values are analyzed and the amplitude and/or phase information is extracted from the filtered interference values.

Systems, devices, and methods for side lobe control in holograms are described. The magnitude of the side lobes of a hologram depends on the distribution of refractive index modulation (Δn), therefore control of side lobe magnitude may be achieved by controlling the distribution of Δn. The distribution of Δn may be controlled by replicating a hologram from a master with two reference beams, where the wavelength and angle of each reference beam, the playback angle of the master hologram, and the thickness of the master hologram, the copy holographic recording medium (HRM), and the recording substrate are carefully chosen to achieve a pattern of meta-interference within the HRM that matches the desired distribution of Δn.

A display including a relief structure forming layer having a major surface with a relief type diffractive structure that displays a three-dimensional object as a diffraction image; and a reflective layer at least partially covering a region of the major surface where the diffractive structure is provided. A portion of the diffractive structure in a first region includes first and second linear parts forming a first lattice, and first parts arranged in respective gaps of the first lattice. The first and second linear parts each having a solid line shape form a first pattern. A portion of the diffractive structure in a second region includes third and fourth linear parts alternately arranged in the width direction thereof. The third linear parts each having a dashed line shape and the fourth linear parts each having a dashed or dotted line shape form a second pattern.

Systems, devices, and methods for aperture-free hologram recording are described. The apertures typically used for hologram recording create unwanted secondary holograms by diffracting light. Aperture-free hologram recording eliminates these unwanted secondary holograms. Aperture-free hologram recording includes applying a mask to the holographic recording medium. The mask controls the size of the recorded hologram like an aperture but does not create unwanted secondary holograms. Hologram fringes are only present in the desired recording area and a thin boundary region. The mask may be present during recording, or the mask may be used to pre-bleach the holographic recording medium. Pre-bleaching the holographic recording medium renders a portion of the holographic recording medium insensitive to light, the hologram is recorded in the light-sensitive portions of the holographic recording medium.

Systems, devices, and methods for aperture-free hologram recording are described. The apertures typically used for hologram recording create unwanted secondary holograms by diffracting light. Aperture-free hologram recording eliminates these unwanted secondary holograms. Aperture-free hologram recording includes applying a mask to the holographic recording medium. The mask controls the size of the recorded hologram like an aperture but does not create unwanted secondary holograms. Hologram fringes are only present in the desired recording area and a thin boundary region. The mask may be present during recording, or the mask may be used to pre-bleach the holographic recording medium. Pre-bleaching the holographic recording medium renders a portion of the holographic recording medium insensitive to light, the hologram is recorded in the light-sensitive portions of the holographic recording medium.

A hologram display system is disclosed. An example system includes a hologram apparatus including a sheet folded along preformed creases into a frustum structure configured to be actuated between a compressed state and an uncompressed state. The frustum structure has a base section and a top section connected by four side sections. The system also includes instructions stored in a memory of a consumer device, which when executed, cause a processor of the consumer device to display, on a screen of the consumer device, holographic interactive content that is related to the hologram apparatus, detect interaction with at least one of the holographic interactive content or the hologram apparatus after the hologram apparatus is placed on the screen of the consumer device, and change the display of at least a portion of the holographic interactive content based on the detected interaction.

A method for producing a hologram (1), (1) for security elements (1a) and/or security documents (1b). One or more virtual hologram planes (10) are arranged in front of and/or behind one or more virtual models (20) and/or one or more virtual hologram planes (10) are arranged such that they intersect one or more virtual models (20). One or more virtual light sources (30) are arranged on one or more partial regions of the surface (21) of one or more of the virtual models (20). One or more virtual electromagnetic fields (40) are calculated starting from at least one of the virtual light sources (30) in one or more zones (11) of the one or more virtual hologram planes (10). In the one or more zones (11), in each case, a virtual total electromagnetic field (41) is calculated on the basis of the sum of two or more, of the virtual electromagnetic fields (40) in the respective zone (11). One or more phase images (50) are calculated from the virtual total electromagnetic fields (41) in the one or more zones (11). A height profile (60) of the hologram (1) is calculated from the one or more phase images (50) and the height profile (60) of the hologram (1) is incorporated into a substrate (2) to provide the hologram (1).

A holographic security or identification device (10) comprises an object, or a flexible substrate (12) configured to be conformable to a desired, curved shape; and a plurality of structures (14) formed on or in the object to have a desired curved configuration, or formed in or associated with the substrate and arranged to adopt a desired curved configuration when the substrate is conformed to a desired shape, wherein the plurality of structures (14) are configured to receive light (20) of a selected at least one wavelength or range of wavelengths and to produce, using the received light, a desired holographic image (22) for security or identification purposes when in the desired configuration.

A mobile hologram apparatus is disclosed. An example apparatus includes a sheet folded along preformed creases into a pyramid structure configured to be actuated between a compressed state and an uncompressed state. The pyramid structure has a base section and a top section connected by four side sections. The pyramid structure in the compressed state has a height that is less than 1/10th the height of the pyramid structure in the uncompressed state. The apparatus also includes an elastic band connected to a perimeter of the base section of the pyramid structure and configured to cause the pyramid structure to self-actuate from the compressed state to the uncompressed state.