Abstract: The present invention relates to a method for improving the image quality of a HUD system, the HUD system comprising an image display device (1) and a reflecting element (3) having a partially transmissive first reflective surface (3a) and at least one partially transmissive second reflective surface (3b) substantially parallel thereto, and a polarization-dependent reflection layer (13) and/or an anti-reflection layer (14) and/or an optical birefringent layer (15), wherein the second reflective surface (3b) is arranged on the side of the first reflective surface (3a) opposite the image display device (1) and wherein the reflecting element (3) is adapted to produce reflected light beams (12a, 12b) from incident light beams (11) which are originating from the points of the image generated by the image display device (1) and arriving at the reflective surfaces (3a, 3b) and to reflect a portion of the reflected light beams (12a, 12b) toward a design detection point (23a), characterized by —determining for each of

Abstract: In one non-limiting embodiment, a transparency for use as a cover plate for a solar collector, window and/or room divider includes a major surface of a glass substrate having Brewster tetrahedrons to convert s-polarized light waves to converted p-polarized light waves to reduce the percent of light wave reflectance of the substrate. In another non-limiting embodiment, the transparency includes a major surface of the substrate having pyramidal tetrahedrons to capture light waves within the body of the substrate to reduce the percent of visible light reflection.

Abstract: In one non-limiting embodiment, a transparency for use as a cover plate for a solar collector, window and/or room divider includes a major surface of a glass substrate having Brewster tetrahedrons to convert s-polarized light waves to converted p-polarized light waves to reduce the percent of light wave reflectance of the substrate. In another non-limiting embodiment, the transparency includes a major surface of the substrate having pyramidal tetrahedrons to capture light waves within the body of the substrate to reduce the percent of visible light reflection.

Abstract: The object of the invention is a phase modulator system comprising a beam splitter and a reflection mode phase modulator suitable for modulating linearly polarised light of at least one specific polarisation state while maintaining said polarisation state. The beam splitter and the phase modulator are arranged along an optical path of a light beam. The beam splitter is a polarisation beam splitter and the phase modulator system further comprises an optical rotator being arranged along the optical path between the polarisation beam splitter and the phase modulator, and rotating the polarisation state of the light beam by 45° in a given sense, wherein the polarisation state of the light beam incident upon the phase modulator corresponds to said specific polarisation state.

Abstract: The invention describes a collinear optical head for a reflection-type holographic recording medium, which is capable of obtaining an increased capacity. The optical head presented here allows for high capacity by combining holographic multiplexing methods, based on a shift and/or phase-coded reference beam, and/or scanned reference beam and/or angle and/or confocal addressing techniques. The parallel reading method and the format of the holographic recording medium ensure high-speed data transfer. Combined multiplexing is implemented in the system by means of a confocal optical arrangement that reduces crosstalk between adjacent holograms by filtering out object beams unintentionally reconstructed from non-addressed holograms.

Abstract: There is disclosed a method and apparatus for coding data, for the purpose of preventing unauthorised readout of information. In the method, user information is converted into digital data (UD), and the digital data is recorded in a first data set (CD) and a second data set (HD), where the first data set (CD) is recorded in a first optical storage medium of a data carrier, and the second data set (HD), is recorded in a second, holographic storage medium of the data carrier. According to the method, the digital data (UD) is divided between the first and second data sets (CD,HD) in a manner so that a part of the user information is contained only in the first data set (CD), and another part of the user information is contained only in the second data set (HD), and the relative proportion of the user information in the data sets is selected so that the information contained in any one of the data sets is insufficient by itself to restore the complete user information (UD) contained in both data sets.

Abstract: The invention describes a collinear optical head for a reflection-type holographic recording medium, which is capable of obtaining an increased capacity. The optical head presented here allows for high capacity by combining holographic multiplexing methods, based on a shift and/or phase-coded reference beam, and/or scanned reference beam and/or angle and/or confocal addressing techniques. The parallel reading method and the format of the holographic recording medium ensure high-speed data transfer. Combined multiplexing is implemented in the system by means of a confocal optical arrangement that reduces crosstalk between adjacent holograms by filtering out object beams unintentionally reconstructed from non-addressed holograms.

Abstract: The present invention relates generally to a method for parallel optical decoding of a digital phase image to an intensity image by algorithmic encoding of a data page into phase image and parallel optical decoding by capturing the interference of the phase data page and its copy shifted by one or a few pixels with respect to each other.

Abstract: The invention relates to a method for the recording and reading of data with a holographic write/read apparatus onto a holographic recording medium with a thin holographic recording layer. The medium is preferably an optical card (2). The recording of the information is in the form of data pages stored as thin Fourier holograms (61). According to the invention, it is foreseen to use reflected transmission and polarisation holography with different write and read wavelengths, and to correct during reading the distortion in the readout channel caused by the difference between the write and read wavelengths. The invention further relates to an apparatus and system for performing the method. There is also disclosed a method of coding the recorded information.

Abstract: The object of the invention is a high data density holographic data storage method. The holograms are written into the volumetric data storage layer or layers, and during the writing process the accurate places of holograms in the data carrier structure are determined by the intersection domain of the object and reference beam or beams, and during the reading process the selection of holograms simultaneously illuminated by the reference beam or beams, the read-out of the addressed hologram, and the suppressing of un-addressed holograms are carried out by a spatial filter located confocally with the addressed hologram and/or by satisfying the Bragg condition. The optical arrangement for recording and reading out holograms has three dedicated planes in confocal arrangements, where the addressed hologram is in the middle dedicated plane in the storage material, and in the two outer dedicated planes there are spatial filters. The optical arrangement is a 12f optical System consisting of three pairs of objectives.

Abstract: There is disclosed a method and apparatus for coding data, for the purpose of preventing unauthorised readout of information. In the method, user information is converted into digital data (UD), and the digital data is recorded in a first data set (CD) and a second data set (HD), where the first data set (CD) is recorded in a first optical storage medium of a data carrier, and the second data set (HD), is recorded in a second, holographic storage medium of the data carrier. According to the method, the digital data (UD) is divided between the first and second data sets (CD,HD) in a manner so that a part of the user information is contained only in the first data set (CD), and another part of the user information is contained only in the second data set (HD), and the relative proportion of the user information in the data sets is selected so that the information contained in any one of the data sets is insufficient by itself to restore the complete user information (UD) contained in both data sets.

Abstract: There is disclosed a method for the holographic recording of data, wherein a hologram containing the date is recorded in a waveguide layer (3). The holograms are formed in a layer structure containing multiple waveguide layers (3). Coupling means (12) are provided for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure. The invention also relates to an arrangement for holographic recording of data, comprising a data storage medium with a waveguide holographic storage layer, and an optical system for writing and reading the holograms. The optical system comprises means for imaging an object beam (5) and a reference beam (11) on the storage medium. The arrangement comprises multiple waveguide holographic storage layers (3) in the storage medium, and means for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure.

Abstract: There is disclosed a method for the holographic recording of data, wherein a hologram containing the date is recorded in a waveguide layer (3). The holograms are formed in a layer structure containing multiple waveguide layers (3). Coupling means (12) are provided for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure. The invention also relates to an arrangement for holographic recording of data, comprising a data storage medium with a waveguide holographic storage layer, and an optical system for writing and reading the holograms. The optical system comprises means for imaging an object beam (5) and a reference beam (11) on the storage medium. The arrangement comprises multiple waveguide holographic storage layers (3) in the storage medium, and means for selectively coupling the reference beam (11) into the single waveguide layers (3) of the layer structure.