Abstract: A translucent construction element comprising a layer of translucent substrate, which contains a surface structured with nanoplanes of inclined angle relative to the substrate plane, and coated with an interrupted metallic layer covering at least a part of said nanoplanes, is characterized by a high density of interruptions in the metallic layer of low thickness; the periodicity of interruptions in the metallic layer generally is from the range 50 to 1000 nm and the thickness of the metallic layer typically is from the range 1 to 50 nm. The construction element may be integrated, for example, into windows, plastic films or sheets or glazings, especially for the purpose of light management.

Abstract: An ultra-thin spectrometer is disclosed for measuring spectra of a sample, including an optical layer including micro-optical elements having each an input acceptance cone of is less than 30°. At least one of the micro-optical elements is configured to provide a deflected light beam that is directed onto at least one of the photodetectors; The spectrometer includes least one continuous-shaped narrow spectral band filter element arranged between the array of micro-optical elements and the plurality of photodetectors, and defines a plurality of different filter portions that have different peak transmission wavelengths for each of the deflected light beams. The spectral resolution of the spectrometer, in its whole spectral width, is less than 50 nm. Also disclosed is a method to determine the spectrum of an incident light beam on the spectrometer.

Abstract: The present invention relates to an element comprising a surface area with a specific, optically effective surface relief microstructure (12). The surface relief microstructure has a surface modulation of top regions (13) and bottom regions (14), wherein in a first lateral direction of the surface area there is in average at least one transition from a top to a bottom region or vice versa within every 20 micrometer, and in a second lateral direction of the mask, which is perpendicular to the first direction, there is in average at least one transition from a first to a second zone or vice versa within every 200 micrometer. In the microstructure, (i) in the first direction the lateral arrangement of the transitions is non-periodic, and (ii) the top regions substantially lie in the same top relief plateau (15) and the bottom regions substantially lie in the same bottom relief plateau (16).

Abstract: A translucent or transparent film or sheet device shows angular-independent IR reflectance, which comprises a substrate (1) covered with a layer of a dielectric high refractive index material (4) containing a thin metallic layer (3) embedded in said material, and a further layer (5) of translucent or transparent material covering said layer (4) of dielectric high refractive index material, characterized in that the embedded metal layer (3) is periodically interrupted with a periodicity of 50 to 800 nm such that metal covers at least 70% of the substrate area. The device may advantageously be integrated into a window, a glass facade element or especially onto a photovoltaic (PV) device, where it reduces the fraction of IR radiation passing into the building, or reduces heat take-up and thus lowers the operating temperature and improves the efficiency of the PV cell.

Abstract: The present invention concerns a method for constructing a light coupling system wherein a grating is manufactured on the surface of a multimode waveguide and defines the entrance of the waveguide for an incident light beam, said grating comprising a repetition of patterns. The grating is defined by a set of parameters comprising: •grating period (P), separating two adjacent patterns, •grating depth (d) between the highest and the lowest point of the pattern, •incident angle mean value (?) of the incident light with respect to the waveguide. The method comprises a step of optimization of the set of parameters to obtain an optimized second set of parameters, in order to obtain a transmission efficiency (Ce) of the incident light into said waveguide for the first or the second diffractive order exceeding 35% for unpolarized light, or exceeding 50% for polarized light, at a given wavelength of the incident light.

Abstract: The invention relates to a grating coupler comprising: —an optical substrate arranged to transfer a light beam, and —a diffraction grating arranged on, or imbedded in, the surface of said optical substrate, said diffraction grating comprising diffraction grating elements comprising each a coating arranged asymmetrically on said diffraction grating elements. The grating coupler is further arranged to satisfy the condition: (n1×sin(I?I)+?2)/?×P>1, wherein n1 is the refractive index of the optical medium to the incident light side of the diffraction grating elements, n2 is the refractive index of the optical medium to the diffracted light side of the diffraction grating elements, lal the absolute value of the incident angle of the light beam incident on the grating coupler ? is the vacuum wavelength of the diffracted light, and P is the period of the diffraction grating elements.

Abstract: The invention relates to a grating coupler comprising: —an optical substrate arranged to transfer a light beam, and—a diffraction grating arranged on, or imbedded in, the surface of said optical substrate, said diffraction grating comprising diffraction grating elements comprising each a coating arranged asymmetrically on said diffraction grating elements. The grating coupler is further arranged to satisfy the condition: (n1×sin(I?I)+?2)/?×P>1, wherein n1 is the refractive index of the optical medium to the incident light side of the diffraction grating elements, n2 is the refractive index of the optical medium to the diffracted light side of the diffraction grating elements, lal the absolute value of the incident angle of the light beam incident on the grating coupler ? is the vacuum wavelength of the diffracted light, and P is the period of the diffraction grating elements.

Abstract: A translucent construction element comprising a layer of translucent substrate, which contains a surface structured with nanoplanes of inclined angle relative to the substrate plane, and coated with an interrupted metallic layer covering at least a part of said nanoplanes, is characterized by a high density of interruptions in the metallic layer of low thickness; the periodicity of interruptions in the metallic layer generally is from the range 50 to 1000 nm and the thickness of the metallic layer typically is from the range 1 to 50 nm. The construction element may be integrated, for example, into windows, plastic films or sheets or glazings, especially for the purpose of light management.

Abstract: The present invention concerns a method for constructing a light coupling system wherein a grating is manufactured on the surface of a multimode waveguide and defines the entrance of the waveguide for an incident light beam, said grating comprising a repetition of patterns. The grating is defined by a set of parameters comprising: •grating period (P), separating two adjacent patterns, •grating depth (d) between the highest and the lowest point of the pattern, •incident angle mean value (?) of the incident light with respect to the waveguide. The method comprises a step of optimization of the set of parameters to obtain an optimized second set of parameters, in order to obtain a transmission efficiency (Ce) of the incident light into said waveguide for the first or the second diffractive order exceeding 35% for unpolarized light, or exceeding 50% for polarized light, at a given wavelength of the incident light.

Abstract: The present invention relates to an element comprising a surface area with a specific, optically effective surface relief microstructure (12). The surface relief microstructure has a surface modulation of top regions (13) and bottom regions (14), wherein in a first lateral direction of the surface area there is in average at least one transition from a top to a bottom region or vice versa within every 20 micrometer, and in a second lateral direction of the mask, which is perpendicular to the first direction, there is in average at least one transition from a first to a second zone or vice versa within every 200 micrometer. In the microstructure, (i) in the first direction the lateral arrangement of the transitions is non-periodic, and (ii) the top regions substantially lie in the same top relief plateau (15) and the bottom regions substantially lie in the same bottom relief plateau (16).

Abstract: The present invention relates to an element comprising a surface area with a specific, optically effective surface relief microstructure (12). The surface relief microstructure has a surface modulation of top regions (13) and bottom regions (14), wherein in a first lateral direction of the surface area there is in average at least one transition from a top to a bottom region or vice versa within every 20 micrometer, and in a second lateral direction of the mask, which is perpendicular to the first direction, there is in average at least one transition from a first to a second zone or vice versa within every 200 micrometer. In the microstructure, (i) in the first direction the lateral arrangement of the transitions is non-periodic, and (ii) the top regions substantially lie in the same top relief plateau (15) and the bottom regions substantially lie in the same bottom relief plateau (16).

Abstract: A structure (100) comprises a transparent substrate (110) having a surface (104), and the surface (104) has a three dimensional pattern (310) resulting from a combination of at least two surface waves (312, 314, 316). The at least two surface waves (312, 314, 316) differ in wavelength by in maximum 50% based on the wavelength of the wave of the at least two surface waves (312, 314, 316) having the bigger wavelength. Each wavelength of the at least two waves (312, 314, 316) is selected from the range of 200 to 900 nm. The structure (100) may be integrated into plastic films or sheets or glazings, especially for the purpose of light management.

Abstract: The present invention relates to an element comprising a surface area with a specific, optically effective surface relief microstructure (12). The surface relief microstructure has a surface modulation of top regions (13) and bottom regions (14), wherein in a first lateral direction of the surface area there is in average at least one transition from a top to a bottom region or vice versa within every 20 micrometer, and in a second lateral direction of the mask, which is perpendicular to the first direction, there is in average at least one transition from a first to a second zone or vice versa within every 200 micrometer. In the microstructure, (i) in the first direction the lateral arrangement of the transitions is non-periodic, and (ii) the top regions substantially lie in the same top relief plateau (15) and the bottom regions substantially lie in the same bottom relief plateau (16).

Abstract: The present invention relates to a new optical component comprising an anisotropic diffuser (5,10) with patterned anisotropy; and means (9, 11, 14, 16, 17, 20, 21, 30, 32) for providing a colorshift observable upon changing viewing angle (6) and/or changing angle of incident light (2). It also relates to methods for making such an optical component and uses of such optical components as security elements with a very high level of security.

Abstract: The present invention relates to an element comprising a surface area with a specific, optically effective surface relief microstructure (12). The surface relief microstructure has a surface modulation of top regions (13) and bottom regions (14), wherein in a first lateral direction of the surface area there is in average at least one transition from a top to a bottom region or vice versa within every 20 micrometer, and in a second lateral direction of the mask, which is perpendicular to the first direction, there is in average at least one transition from a first to a second zone or vice versa within every 200 micrometer. In the microstructure, (i) in the first direction the lateral arrangement of the transitions is non-periodic, and (ii) the top regions substantially lie in the same top relief plateau (15) and the bottom regions substantially lie in the same bottom relief plateau (16).

Abstract: The present invention relates to a new optical component comprising an anisotropic diffuser (5,10) with patterned anisotropy; and means (9, 11, 14, 16, 17, 20, 21, 30, 32) for providing a colourshift observable upon changing viewing angle (6) and/or changing angle of incident light (2). It also relates to methods for making such an optical component and uses of such optical components as security elements with a very high level of security.

Abstract: A liquid crystal electrooptical element is disclosed that comprises a pair of substrates positioned between a pair of polarising plates, electrodes defining pixel areas and alignment layers disposed on the respective opposing inside surfaces of the substrates, and a chiral nematic liquid crystal sandwiched between the pair of surfaces. At least one of the alignment layers may be patterned in such a way that the azimuth or pretilt or both alignment directions are different at the substrate interfaces suppressing the growth of the ground state of the liquid crystal. When an initial electrical pulse is applied, one of the at least two bistable states can be reached, wherein the contrast ratio between the bistable states is two or greater. A device with such features is long-term bistable and does not require electronic refreshing as long as the displayed information is not changed. Therefore, the power consumption of this bistable device is minimal.

Abstract: A liquid crystal electrooptical element comprises a pair of substrates (20, 21) positioned between a pair of polarising plates, electrodes defining pixel areas (1) and alignment layers disposed on the respective opposing inside surfaces of said substrates (20, 21) and a chiral nematic liquid crystal sandwiched between said pair of surfaces. At least one of the alignment layers is patterned in such a way that the azimuth or pretilt or both alignment directions (14 to 17, 16 to 18) are different at the substrate interfaces suppressing the growth of the ground state of the liquid crystal. When an initial electrical bistable states is reached, wherein the contrast ratio between said bistable states is two or greater. A device with these elements is long-term bistable and does not require electronic refreshing as long as the displayed information is not changed. Therefore, the power consumption of this bistable device is minimal.

Abstract: A liquid crystal device comprising ferroelectric liquid crystal material aligned by a liquid crystal polymer (LCP) network layer (18) under 20 nm thick, which itself was aligned by a photo-oriented linearly photopolymerized (LPP) layer (16) under 20 nm thick, exhibits low voltage drop over the aligning layer and has a remarkable contrast ratio.

Abstract: The present invention is related to a Wollaston prism (WP) comprising two birefringent wedges (W1, W2) joined by their hypotenuse to form a composite block, said wedges having optic axes (OA1, OA2) to each other at right angle. According to the invention, the optic axes (OA1, OA2) of said wedges (W1, W2) are rotated by an angle of 45° or 135°, respectively, with regard to a position wherein one of the optic axes (OA1, OA2) lies parallel to the plane formed by the hypotenuse. In an embodiment of the present invention, liquid crystal is used as material for the wedges (W1, W2) resulting in inexpensive and easy to handle Wollaston prisms.