Abstract: The invention relates to a device (4) in the form of a medical prosthesis (9, 17), medical osteosynthesis device, hearing aid or hearing aid housing, essentially made of metal, wherein the device (4, 9, 17) comprises at least one optical diffractive element with a grating (6) which is directly embossed in an exposed metal surface in the form of a security and/or identification element. The invention furthermore relates to methods for making such devices and to uses of such devices.

Abstract: The invention relates to a method for producing a metal stamp for embossing a nano- or microstructure on a metal device (4), comprising the following steps for producing a 3D structured embossing area (3) on the stamp: a) providing a master (30) having a structured surface (30a), and replicating said master (30a) in the surface of a soft stamp (31); b) forming an imprint (32) on the soft stamp (31a) using a cross-linkable material to form an imprint structured surface (32a), before, while or after contacting an opposite side of the imprint (32) with said surface portion of the metal stamp, and removing said soft-stamp (31) exposing said imprint structured surface (32a); c) etch-opening said surface (32a) using a first set of etching conditions; d) using a second set of etching conditions, different from the first ones, etching the surface of the metal stamp to form said embossing area (3).

Abstract: A tamper seal includes an optical waveguide arranged to guide a propagating light-beam along a propagation direction. First and second portions of the tamper seal are configured to be arranged on first and second parts, respectively, which are movable relative to each other. The first portion has an input coupler arranged to couple incident light into the optical waveguide, and the second portion has at least one output coupler arranged to couple out of the optical waveguide at least partially light guided in the optical waveguide. The input coupler, the optical waveguide, and the output coupler are configured to transmit light from the input coupler to the output coupler. The waveguide is configured to be disruptable and includes a layer having a distinctive appearance that is changed in response to an at least partial disruption of said optical waveguide.

Abstract: A tamper seal includes an optical waveguide arranged to guide a propagating light-beam along a propagation direction. First and second portions of the tamper seal are configured to be arranged on first and second parts, respectively, which are movable relative to each other. The first portion has an input coupler arranged to couple incident light into the optical waveguide, and the second portion has at least one output coupler arranged to couple out of the optical waveguide at least partially light guided in the optical waveguide. The input coupler, the optical waveguide, and the output coupler are configured to transmit light from the input coupler to the output coupler. The waveguide is configured to be disruptable and includes a layer having a distinctive appearance that is changed in response to an at least partial disruption of said optical waveguide.

Abstract: A tablet for pharmaceutical use has on at least one part of its surface a diffractive microstructure which generates diffraction effects which can be perceived in the visible spectral range and which serve as visual safety feature. The tablet includes a plurality of individual powder particles, where the diffractive microstructures are impressed into the surface of the individual powder particles. A compression tool to produce such tablets has on one pressing surface of the compression tool micro-structures, where the microstructures have dimensions which are smaller than the dimensions of the individual crystallites of the material of the pressing surface of the compression tool. The micro-structures of the compression tool can be produced for example by ion etching or by imprinting.

Abstract: A tamper seal includes an optical waveguide arranged to guide a propagating light-beam along a propagation direction. First and second portions of the tamper seal are configured to be arranged on first and second parts, respectively, of an object, said first and a second parts being movable relative to each other. The first portion comprises an input coupler arranged to couple incident light into said optical waveguide. The second portion includes at least one outcoupling surface arranged to couple out at least partially light guided in the optical waveguide. The input coupler, optical waveguide and outcoupling surface are arranged to transmit light from the input coupler to the outcoupling surface. The optical waveguide is further designed to be at least partially disruptable between the two portions, wherein the optical waveguide loses or at least partially changes its optical guiding properties after its disruption.

Abstract: The present invention is in the field of security documents, more particularly in the field of security elements aimed to protect security documents against copying (illegal reproduction) and counterfeiting. It discloses a security element having a security feature which changes its visual appearance after irradiation with light, especially with UV light and at rotation and/or tilting. Security documents comprising said security element, as well as a method for producing said security element, are also disclosed.

Abstract: A sensor which reacts on influences from an environment. The sensor includes a zero-order diffractive color filter. The zero-order diffractive color filter includes a high-index waveguide layer, a zero-order diffractive grating structure and a layer of an reactive material, wherein the reactive material is in contact with the environment and wherein the reactive material changes its optical properties upon interaction with the environment. The reactive material is embedded in the waveguide layer and/or the reactive material is located at a maximum distance d from the waveguide layer. The distancing is effected by an intra layer having a low index of refraction.

Abstract: A security device including a zero order diffractive microstructure buried within a substrate. One or more optical structures, such as microlenses, may be formed on a surface of the substrate. The optical structures modify the optical characteristics of the zero order diffractive microstructure. Various alternatives or additional optical structures and methods of producing the security device are described in additional embodiments.

Abstract: A security Device comprises a zero order diffractive microstructure (5) buried within a substrate (3). One or more further optical structures, such as microlenses (1), may be formed on a surface (2) of the substrate (3). The further optical structures modify the optical characteristics of the zero order diffractive microstructure (5). Various alternatives or additional optical structures and methods of producing them are described in additional embodiments.

Abstract: The present invention is in the field of security documents, more particularly in the field of security elements aimed to protect security documents against copying (illegal reproduction) and counterfeiting. It discloses a security element having a security feature which changes its visual appearance after irradiation with light, especially with UV light and at rotation and/or tilting. Security documents comprising said security element, as well as a method for producing said security element, are also disclosed.

Abstract: A security Device comprises a zero order diffractive microstructure (5) buried within a substrate (3). One or more further optical structures, such as microlenses (1), may be formed on a surface (2) of the substrate (3). The further optical structures modify the optical characteristics of the zero order diffractive microstructure (5). Various alternatives or additional optical structures and methods of producing them are described in additional embodiments.

Abstract: A security Device comprises a zero order diffractive microstructure (5) buried within a substrate (3). One or more further optical structures, such as microlenses (1), may be formed on a surface (2) of the substrate (3). The further optical structures modify the optical characteristics of the zero order diffractive microstructure (5). Various alternatives or additional optical structures and methods of producing them are described in additional embodiments.

Abstract: A security device comprises a zero order diffractive microstructure buried within a substrate. One or more further optical structures, such as microlenses, may be formed on a surface of the substrate. The further optical structures modify the optical characteristics of the zero order diffractive microstructure such as by enhancing or reducing the color effect produced by the zero-order diffractive microstructure upon tilting the security device.

Abstract: A color image sensor has a plurality of pixels. On the pixels zero-order diffractive color filters (DCFs) (1) are arranged. Different zero-order DCFs (1), e.g., DCFs (1) transmitting red, green and blue light, respectively, are allocated to the pixels of the color image sensor. The use of DCFs (1) for color imaging devices brings better defined band-pass or notch filters than the presently used lacquers. The DCFs (1) are more stable with respect to time, temperature and any environmental aggression. The manufacture of the DCF pattern is simpler and cheaper than that of a conventional dye-filter pattern, since the different types of DCFs can be manufactured simultaneously.

Abstract: The diffractive optical device (1) can be used as a security device in the fields of authentication, identification and security. It comprises a zero-order diffractive color filter (3). The diffractive color filter may consist of a microstructured high-index layer (32) embedded between two low-index layers (31, 33). A mirror layer (4) for reflecting towards the diffractive color filter (3) at least part of light transmitted through the diffractive color filter (3) are provided beneath the diffractive color filter. Thanks to the mirror layer (4), the device (1) has a much higher reflected intensity and much more complex spectra than prior-art diffractive color filters.

Abstract: A security device comprises first zero order diffractive microstructure (1) on a substrate, a second zero order diffractive microstructure (2), and an intermediate light transmissive layer (4) separating the two diffractive microstructures. The spacing (sn,n+1) between the first (1) and second (2) diffractive microstructures is small enough so that optical interferences are produced between the diffractive microstructures. A further light transmissive layer (3) covers the second diffractive microstructure (2).

Abstract: A tablet (4) for pharmaceutical use has on at least one part of its surface a diffractive microstructure (11) which generates diffraction effects which can be perceived in the visible spectral range and which serve as visual safety feature. The tablet (4) consists of a plurality of individual powder particles, where the diffractive microstructures (11) are impressed into the surface of the individual powder particles. A compression tool (1, 1a, 1b, 3) to produce such tablets (4) has on one pressing surface of the compression tool (1, 1a, 1b, 3) micro-structures (11), where said microstructures (11) have dimensions which are smaller than the dimensions of the individual crystallites (30) of the material of the pressing surface of the compression tool (1, 1a, 1b, 3). The micro-structures (11) of the compression tool can be produced for example by ion etching or by imprinting.

Abstract: A sensor which reacts on influences from an environment. The sensor includes a zero-order diffractive color filter. The zero-order diffractive color filter includes a high-index waveguide layer, a zero-order diffractive grating structure and a layer of an reactive material, wherein the reactive material is in contact with the environment and wherein the reactive material changes its optical properties upon interaction with the environment. The reactive material is embedded in the waveguide layer and/or the reactive material is located at a maximum distance d from the waveguide layer. The distancing is effected by an intra layer having a low index of refraction.

Abstract: An article (1) such as a medicinal tablet or a foodstuff, has a microstructured surface (2). White light incident on the microstructure will be reflected at a number of different wavelengths dependent on the angle of incidence of the white light on the structure. This structure can provide an indication of authenticity of the article.