Abstract: An optical display system and an augmented reality electronic device are disclosed. The optical display system comprises: a waveguide; an input coupler, provided at the input end of the waveguide and couples an image light into it; and a two-dimensional grating, provided at the output end of waveguide. The waveguide delivers the image light to the two-dimensional grating, which performs pupil expansion on the image light and out-couples the expanded image light. The two-dimensional grating has rhombus lattices. Unit cells of the two-dimensional grating are un-symmetric along respective axes parallel with a propagation direction of the image light incident onto the two-dimensional grating, from a top view of the two-dimensional grating. The unit cells are oriented with the propagation direction of the image light and each of the unit cells has at least two vertexes at its end side.

Abstract: An optical waveguide for a head up display having two optical input regions. Optical gratings direct light injected into the optical input regions towards and output region and to be trapped in the optical waveguide by total internal reflection. Beam splitters are provided to expand the pupil in two dimensions. Light from each input region is directed to different areas of the output region.

Abstract: A display apparatus including a display panel, a camera module, and a diffraction suppression device is provided. The display panel is provided with multiple signal lines and multiple display pixels. The signal lines and the display pixels are alternately arranged along at least one direction. The camera module has a light receiving surface facing the display panel. The light receiving surface is overlapped with the display panel. The diffraction suppression device is disposed between the display panel and the camera module, and has multiple first light-transmitting regions and multiple second light-transmitting regions alternately arranged along the at least one direction. The first light-transmitting regions are respectively overlapped with the display pixels. The second light-transmitting regions are respectively overlapped with the signal lines.

Abstract: As described above, one or more aspects of the present disclosure provide articles having structural achromatic color, and methods of making articles having structural achromatic color. The present disclosure provides for articles that exhibit structural color upon exposure to white light (e.g., sunlight, artificial light, or a combination) that shifts based on the angle of observation and/or incident light. At least one shift in the structural color is between an achromatic structural color and a chromatic structural color. The shift occurs at different angles of observation and/or angle of incident light.

Abstract: The present invention discloses a display including a display panel and a light redirecting film disposed on the viewing side of the display panel. The light redirecting film comprises a light redistribution layer, and a light guide layer disposed on the light redistribution layer. The light redistribution layer includes a plurality of strip-shaped micro prisms extending along a first direction and arranged at intervals and a plurality of diffraction gratings arranged at the bottom of the intervals between the adjacent strip-shaped micro prisms, wherein each of the strip-shaped micro prisms has at least one inclined light-guide surface, and the bottom of each interval has at least one set of diffraction gratings, and the light guide layer is in contact with the strip-shaped micro prisms and the diffraction gratings.

Abstract: As described above, one or more aspects of the present disclosure provide articles having structural achromatic color, and methods of making articles having structural achromatic color. The present disclosure provides for articles that exhibit structural color upon exposure to white light (e.g., sunlight, artificial light, or a combination) that shifts based on the angle of observation and/or incident light. At least one shift in the structural color is between an achromatic structural color and a chromatic structural color. The shift occurs at different angles of observation and/or angle of incident light.

Abstract: As described above, one or more aspects of the present disclosure provide articles having structural achromatic color, and methods of making articles having structural achromatic color. The present disclosure provides for articles that exhibit structural color upon exposure to white light (e.g., sunlight, artificial light, or a combination) that shifts based on the angle of observation and/or incident light. At least one shift in the structural color is between an achromatic structural color and a chromatic structural color. The shift occurs at different angles of observation and/or angle of incident light.

Abstract: A method for designing a phase-typed diffraction suppressing optical device (12) for a transparent display screen(11) is disclosed, which comprises: acquiring a light field complex amplitude distribution U(x2,y2,d)=A(x2,y2,d)exp(i?20(x2,y2,d)) on a plane with a distance d from the transparent display screen (12) after a plane wave is transmitted through the screen; and designing the diffraction suppressing optical device (12), so that it has a transmittance function t2 (x2,y2)=exp(i?21(x2,y2)) and satisfies ?20 (x2,y2,d)+?21 (x2,y2)=C, where C is a constant. A diffraction suppressing optical device (12) and an under-screen camera apparatus (1) comprising the same are disclosed. The phase-typed diffraction suppressing optical device (12) suppresses the diffraction effect in the under-screen camera apparatus (1) by providing phase modulation, thereby improving the quality of under-screen imaging.

Abstract: A waveguide is disclosed for use in an augmented reality or virtual reality display. The waveguide includes a plurality of optical structures (10, 20, 30, 40, 50, 60, 70, 80) exhibiting differences in refractive index from a surrounding waveguide medium. The optical structures are arranged in an array to provide at least two diffractive optical elements (H1, H2) overlaid on one another in the waveguide. Each of the two diffractive optical elements is configured to receive light from an input direction and couple it towards the other diffractive optical element which can then act as an output diffractive optical element, providing outcoupled orders towards a viewer. The optical structures have a shape, when viewed in the plane of the waveguide, comprising a plurality of substantially straight sides having respective normal vectors at different angles and this can effectively reduce the amount of light that is coupled out of the waveguide on first interaction with the optical structures.

Abstract: Disclosed are a waveguide display module, and an image generation module and application corresponding thereto. By wavelength division multiplexing, an image generation unit generates through modulation mixed light beams containing at least two groups of sub-images of different wavelengths. The mixed light beams generated through modulation by the image generation unit are coupled into a waveguide module, which module has in-coupling units arranged in multiple layers and out-coupling units arranged in multiple layers, an in-coupling unit in each layer being configured to couple in light of different wavelength ranges. Emergent images, formed after mixed light beams of an image to be displayed generated by the image generation unit are coupled out by the out-coupling units of the waveguide module, are spliced into the image to be displayed.

Abstract: A waveguide display disposed in glasses includes a first pupil expander assembly operable to project a first image defined by a first field of view, and a second pupil expander assembly disposed adjacent the first pupil expander assembly and operable to project a second image defined by a second field of view different from the first field of view. The first pupil expander assembly is operable to emit light at a first non-zero angle with respect to a first emission plane associated with the first pupil expander assembly. The second pupil expander assembly is operable to emit light at a second non-zero angle with respect to a second emission plane associated with the second pupil expander assembly. The first non-zero angle is opposite to the second non-zero angle.

Abstract: A security element with one or more first microstructures, wherein the first microstructures are provided in each case in one or more tracks which are curved at least in sections or in one or more sections of a track which are curved at least in sections, and/or in each case run along one or more tracks which are curved at least in sections or along one or more sections of a track which are curved at least in sections, and a method, wherein at least one file containing image points of one or more image elements is provided, which includes the locational arrangement of the image points, and one or more tracks which are curved at least in sections or one or more sections of one or more tracks which are curved at least in sections are determined from the locational arrangement of the image points, and in the one or more tracks or sections of tracks in each case one or more first microstructures are provided which, when illuminated, provide a first item of optically variable information.

Abstract: An electronic apparatus comprises a display panel defined by a display area and a non-display area surrounding the display area, including at least one hole formed in the display area, an optical module arranged below the display panel and overlaps with the at least one hole, a light source module arranged at one side of the optical module, and an optical member arranged between the at least one hole and the light source module and partially overlaps with each of the at least one hole and the light source module, wherein the optical member emits a light source or image output from the light source module toward the at least one hole.

Abstract: The present invention provides an apparatus (3) comprising a first out-coupling diffractive optical element (10) and a second out-coupling diffractive optical element (20). Each of the first and second out-coupling diffractive optical elements comprises a first region (12a, 22a) having a first repeated diffraction spacing, d1, and a second region (12b, 22b) adjacent to the first region having a second repeated diffraction spacing, d2, different from the first spacing, d1. The first region (12a) of the first out-coupling diffractive optical element (10) is superposed on and aligned with the second region (22b) of the second out-coupling diffractive optical element (20). The second region (12b) of the first out-coupling diffractive optical element (10) is superposed on and aligned with the first region (22a) of the second out-coupling diffractive optical element (20).

Abstract: A head up display can be used in compact environments. The head up display includes a combiner system including at least one light pipe and a waveguide. The at least one light pipe includes a diffraction grating or mirror array for providing light into the waveguide from the light pipe. The light pipe is configured to receive light and provide first light in a first direction for a first field of view and second light in a second direction for a second field of view. The combiner system can be head worn or stand-alone and can provide dual axis pupil expansion.

Abstract: There is provided an optical element for counterfeit prevention that has both high counterfeit preventing property and designability by a multi-optical element structure. The optical element has a second layer (3) having a relief structure on a front surface, a first layer (2) disposed on the second layer (3), and a third layer (6) in a thin film interposed between the second layer (3) and the first layer (2) and formed along a front surface of the relief structure. The second layer (3) has a refractive index lower than a refractive index of the first layer (2) and the third layer (6) has a refractive index higher than the refractive index of the first layer (2). The optical element has at least a first region (4) and a second region (5) in a plan view. In the first region (4), an electromagnetic wave that enters from a side of the first layer (2) in a specific angle range is configured to be totally reflected.

Abstract: This invention aims to provide a novel laminate in which a first layer is formed with high positional accuracy, and to provide a manufacturing method thereof. In the laminate of this invention, a relief structure forming layer includes a first region having an indented structure extending in a first direction or a direction tilted by an angle within 10 degrees to the left or right from the first direction in a plan view, and a second region including an indented structure extending in a second direction orthogonal to the first direction or a direction tilted by an angle within 65 degrees to the left or right from the second direction in a plan view. The first layer contains a first material which is different from a material of the relief structure forming layer, and has a surface shape corresponding to that of the relief structure forming layer.

Abstract: In an optical display system that includes a waveguide with multiple diffractive optical elements (DOEs), gratings in one or more of the DOEs may have an asymmetric profile in which gratings may be slanted or blazed. Asymmetric gratings in a DOE can provide increased display uniformity in the optical display system by reducing the “banding” resulting from optical interference that is manifested as dark stripes in the display. Banding may be more pronounced when polymeric materials are used in volume production of the DOEs to minimize system weight, but which have less optimal optical properties compared with other materials such as glass. The asymmetric gratings can further enable the optical system to be more tolerant to variations—such as variations in thickness, surface roughness, and grating geometry—that may not be readily controlled during manufacturing particularly since such variations are in the submicron range.

Abstract: Systems, devices, and methods for aligning a diffractive element in a wearable heads-up display (“WHUD”) are described. A WHUD that includes a projector, a transparent combiner, a WHUD frame, and a diffractive optical element (DOE) embedded in the transparent combiner, requires alignment between the DOE and the eye of the user and/or the projector. A WHUD includes a DOE aligned with an eye of a user when the WHUD is worn on the head of the user. A method of aligning a DOE in a WHUD with an eye of a user when the WHUD is worn on a head of a user includes aligning a first part of the WHUD frame with a first part of the face of the user, and aligning the DOE with a second part of the WHUD frame.

Abstract: A laminate comprising an abrasion resisting layer that is disposed on a surface of an optically transmissive substrate, wherein the layer comprises a pattern of spatially separated protrusions of an abrasion-resistant material extending away from the surface, and silica interposed between the protrusions. The abrasion-resistant material has a Knoop hardness measured according to ASTM E384 Knoop Hardness Standard that is greater than that of the silica.

Abstract: A waveguide display includes multiple diffractive optical elements (DOEs) that are configured to in-couple image light, provide expanded exit pupil in two directions, and out-couple the image light to a user. An in-coupling DOE is configured to split the full field of view (FOV) of the image light into left and right portions. The left and right FOV portions are respectively propagated laterally in left and right directions in intermediate DOEs which comprise upper and lower portions. The intermediate DOEs provide for exit pupil expansion in a horizontal direction while coupling light to an out-coupling DOE. The out-coupling DOE provides for exit pupil expansion in a vertical direction and out-couples image light with expanded exit pupil for the full FOV. The intermediate DOE portions are configured to steer image light back towards the center of the waveguide to avoid dark areas or stripes in portions of the out-coupling DOE.

Abstract: A head-mounted imaging apparatus includes a frame that houses a left-eye and a right-eye imaging apparatus. Each imaging apparatus forms a virtual image to an eye of an observer and includes a projector, a planar waveguide, and an optical coupler. The projector is supported by a temple member of the frame and emits a central projected light beam along a projection axis. The planar waveguide accepts the projected light beam through an input aperture and forms an expanded light beam that is output from an output aperture and directed toward the observer's eye. The optical coupler receives the central projected light beam along a first axis that is at an obtuse angle with respect to the waveguide surface, and the optical coupler redirects the central projected light beam along a second axis that is at an acute angle with respect to the waveguide surface.

Abstract: A diffraction element can be employed in a surface display unit to provide diffraction peaks in a manner that reduces or eliminates a screen door effect that is prevalent in pixelated displays that does not have sufficient pixel density. The parameters of the diffraction element can be selected such that the diffraction peaks provide appearance of a larger pixel area than a corresponding physical pixel size. For example, first order diffraction peaks can be placed at a distance of about ? of a nearest subpixel-to-sub-pixel distance. The surface display unit can be employed for any image display application to enhance image quality. For example, a virtual reality headset to remove the screen door effect.

Abstract: The display of the present invention includes an uneven-structure-forming layer having a surface provided with a plurality of concavities or a plurality of convexities respectively provided with flat bottoms and flat tops substantially parallel to the flat bottoms, and a light reflecting layer covering all or a part of an uneven surface of the uneven-structure-forming layer. The uneven-structure-forming layer is provided with two kinds of uneven-structure-forming regions. Each of the two kinds of uneven-structure-forming regions has a constant optical distance between the flat bottoms and the flat tops, but the optical distance is different between the two kinds of regions. The two kinds of uneven-structure-forming regions are alternately arrayed.

Abstract: A movable device includes a reflector; a movable section including the reflector; a first drive section connected to the movable section, the first drive section configured to drive the movable section; a first support connected to the first drive section to support the first drive section; and two adjusters disposed symmetrically with respect to the reflector.

Abstract: A display system includes a waveguide having a first diffractive optical element and a second diffractive optical element. The waveguide is configured to receive a display light having a pupil height and pupil width and transmit the display light to an eyebox with an eyebox height and an eyebox width. The first diffractive optical element is configured to in-couple the display light into the waveguide, the first diffractive optical element having a first diffractive optical element height that is at least the pupil height and a first diffractive optical element width that is at least the eyebox width.

Abstract: Images perceived to be substantially full color or multi-colored may be formed using component color images that are distributed in unequal numbers across a plurality of depth planes. The distribution of component color images across the depth planes may vary based on color. In some embodiments, a display system includes a stack of waveguides that each output light of a particular color, with some colors having fewer numbers of associated waveguides than other colors. The stack of waveguides may include by multiple pluralities (e.g., first and second pluralities) of waveguides, each configured to produce an image by outputting light corresponding to a particular color. The total number of waveguides in the second plurality of waveguides is less than the total number of waveguides in the first plurality of waveguides, and may be more than the total number of waveguides in a third plurality of waveguides, in embodiments where three component colors are utilized.

Abstract: MicroLED arrays offer a small form factor solution for the HMD image sources since they do not need a separate illumination optics. Features of the present disclosure implement a MicroLED display system that incorporate a plurality of monochrome projectors (e.g., three MicroLED projectors) to generate three monochrome images (e.g., red, blue, and green images) that are separately input into a single waveguide of the HMD and combined to form an image that is displayed to the user. By utilizing a single waveguide that includes a plurality of spatially separated input regions (e.g., a region for inputting blue light, a region for inputting red light, a region for inputting green light), the MicroLED display system of the present disclosure may reduce the form factor of the HMD device because of the reduced number of plates that may be required to combine the three monochrome images.

Abstract: A method for displaying a near-eye light field display (NELD) image is disclosed. The method comprises determining a pre-filtered image to be displayed, wherein the pre-filtered image corresponds to a target image. It further comprises displaying the pre-filtered image on a display. Subsequently, it comprises producing a near-eye light field after the pre-filtered image travels through a microlens array adjacent to the display, wherein the near-eye light field is operable to simulate a light field corresponding to the target image. Finally, it comprises altering the near-eye light field using at least one converging lens, wherein the altering allows a user to focus on the target image at an increased depth of field at an increased distance from an eye of the user and wherein the altering increases spatial resolution of said target image.

Abstract: An optical system for a colour head up display, the optical system being for guiding image light from an image projection system to an exit pupil. First and second waveguides are utilised, each waveguide guiding a predetermined set of wavelengths.

Abstract: A screen (3) for an HMD (1) is provided, and may be designed as a display screen or as a projection screen. The screen (3) comprises a layer (19) of a material with a switchable degree of transparency and at least one further switchable layer (17, 21, 23) which, in dependence on the switching state, can assume at least two physical states, the physical states differently influencing at least one optical property of light passing through the switchable layer or reflected by it.

Abstract: An optical waveguide including an input-coupler, a first intermediate-component, a second intermediate-component and an output-coupler is described herein. The input-coupler couples, into the waveguide, light corresponding to an image associated with an input-pupil and directs the light toward the first intermediate-component. The first intermediate-component performs horizontal or vertical pupil expansion and redirects the light corresponding to the image toward the output-coupler. The second intermediate-component is a diffractive component located between the first-intermediate component and the output-coupler and performs pupil redistribution on a portion of the light corresponding to the image before the portion reaches the output-coupler. The output-coupler performs the other one of horizontal or vertical pupil expansion and couples, out of the waveguide, the light corresponding to the image. Related methods and systems are also described.

Abstract: A display system is disclosed for use in an augmented reality display (30), the system comprises a waveguide (32) having a front surface and a rear surface. A front input projector (34) projects polychromatic light through a front surface, and a back input projector (36) projects polychromatic light through the rear surface. Input light impinges on an input grating (38) on a rear surface of the waveguide (32), and light travels through the waveguide by total internal reflection. An output grating (40) is provided for coupling light out of the waveguide. A plurality of front and back input projectors (34, 36) are provided in a staggered configuration along the width of the waveguide (32) and respective edges of adjacent front and back input projectors are aligned along the width of the waveguide to permit a continuous projection of light.

Abstract: Systems and methods to provide an interactive environment are presented herein. The system may include one or more of a device configured to be installed on a user's head, an image-forming component, one or more physical computer processors, and/or other components. The image-forming component may be configured to generate light rays to form images. The light rays may be reflected off an optical element towards a user's eye. The light rays may be transmitted back through a portion of the image-forming component before reaching the eye.

Abstract: A non-telecentric display system that prevents ghost images includes an optical waveguide and a display engine. An image former of the display engine includes a reflective surface having a surface normal thereto. An illumination engine of the display engine emits light towards the reflective surface of the image former such that chief rays are offset by acute angles from the surface normal to the reflective surface. The display engine directs light corresponding to an image, that reflects off the reflective surface of the image former, towards an input-coupler of the optical waveguide so light corresponding to the image is coupled therein and travels by total internal reflection to an output-coupler of the waveguide. Ghost images are prevented at least in part due to the chief rays of light emitted by the illumination engine being offset by acute angles from the surface normal to the reflective surface.

Abstract: A cover window covering a display panel of a display device comprises a base member covering a display area and a non-display area of the display panel, and an inorganic layer disposed on the base member. The inorganic layer has substantially uniform thickness on the display area, and has a diffraction grating structure on the non-display area.

Abstract: A method for calibrating includes obtaining a head-mounted display device that includes an electronic display having an array of display elements and an array of beam steerers located over an inner left portion and an inner right portion of the electronic display. The method also includes obtaining alignment information by selecting a first respective subset of the array of display elements and causing it to emit light, and determining whether the light is received by a first optical sensor in a first position or a second optical sensor in a second position, thereby determining whether the first respective subset of the array of display elements is aligned for the first or the second optical sensor. The method also includes repeating the selecting, causing, and determining operations for a second subset of the array of display elements, and storing the alignment information for calibrating images for presentation by the electronic display.

Abstract: A display includes light-scattering regions. Each of the light-scattering regions is provided with linear protrusions and/or recesses having the same longitudinal direction. The light-scattering regions are different from each other in the longitudinal direction.

Abstract: A backlight module includes: a light guide plate; a light source for emitting light rays towards a first region of the light guide plate; a first grating provided at the first region and configured to adjust propagation directions of the light rays such that the adjusted light rays travel towards a second region of the light guide plate, and the propagation directions make an included angle with a normal to the light guide plate which is greater than the critical angle of total reflection of the light guide plate; and a second grating provided at the second region and configured to collimate the adjusted light rays such that the collimated light rays travel in a direction perpendicular to the light guide plate.

Abstract: An optical element includes a plurality of partially reflecting mirrors provided in parallel to each other with an interval therebetween, and a transmittance member interposed between adjacent two partially reflecting mirrors of the plurality of partially reflecting mirrors. The transmittance member has an incidence surface on which an image light and an external light are incident through a light guiding body, and an exit surface from which the image light and the external light are exited to an observer side. Each of the plurality of partially reflecting mirrors is disposed so as to be inclined with respect to the incidence surface and the exit surface, and a reflectance of light incident at a relatively small incidence angle with respect to surfaces of each partially reflecting mirror is lower than a reflectance of light incident at a relatively large incidence angle.

Abstract: Disclosed are an apparatus and method for providing additional degrees of freedom for diffraction gratings of an output waveguide in a near-eye display device. The near-eye display device includes an imager to generate an image based on light from a light source. The device further includes a waveguide to input a light wave representing the image received from the imager and to output the light wave representing the image toward an optical receptor of a user. The waveguide includes a plurality of diffractive optical elements (DOEs) in a common light path from an input of the waveguide to an output of the waveguide. The DOEs include a plurality of periodic diffraction patterns. Each of the periodic diffraction patterns is represented by a diffraction pattern vector. The periodic diffraction patterns are determined such that a vector summation of the diffraction pattern vectors equals zero.

Abstract: A combustible heat source for a smoking article and a method of manufacturing a combustible heat source are provided. The combustible heat source includes a barrier affixed to an end face of the combustible heat source, wherein a thermally-activated adhesive is provided between the end face and the barrier. The method includes providing a thermally-activatable adhesive between the end face of the combustible heat source and the barrier; affixing the barrier to the end face; and heating the combustible heat source with the barrier affixed to the end face thereof to activate the thermally-activatable adhesive.

Abstract: The invention concerns a film element having a replication layer (43), wherein an optically active surface structure (27) is shaped in a first surface of the replication layer. The surface structure is formed in at least a first region of the film element (35) by a first diffractive surface relief (46) comprising a plurality of successive elements following a first envelope curve (47), wherein the elements respectively comprise an element surface (48) arranged substantially parallel to a base surface and at least one flank adjoining the adjacent element surface or surfaces, the element surfaces (48) of adjacent elements are spaced in a direction perpendicular to the base plane, with a first optical spacing or a plurality of the first optical spacing, wherein the first optical spacing is between 150 nm and 800 nm, preferably between 150 nm and 400 nm.

Abstract: A near-eye optical display system utilizes a compact display engine that couples image light from an imager to a waveguide-based display having diffractive optical elements (DOEs) that provide exit pupil expansion in two directions. The display engine comprises a pair of single axis MEMS (Micro Electro Mechanical System) scanners that are configured to reflect the image light through horizontal and vertical scan axes of the display system's field of view (FOV) using raster scanning. The MEMS scanners are arranged with their axes of rotation at substantially right angles to each other and operate with respective quarter wave retarder plates and a polarizing beam splitter (PBS) to couple the image light into an in-coupling DOE in the waveguide display without the need for additional optical elements such as lenses or relay systems.

Abstract: A near-eye optical display system utilizes a compact display engine that couples image light from an imager to a waveguide-based display having diffractive optical elements (DOEs) that provide exit pupil expansion in two directions. The display engine comprises a pair of single axis MEMS (Micro Electro Mechanical System) scanners that are configured to reflect the image light through horizontal and vertical scan axes of the display system's field of view (FOV) using raster scanning. The MEMS scanners are arranged with their axes of rotation at substantially right angles to each other and operate with respective quarter wave retarder plates and a polarizing beam splitter (PBS) to couple the image light into an in-coupling DOE in the waveguide display without the need for additional optical elements such as lenses or relay systems.

Abstract: To make it possible to emit a light pattern with a uniform light quantity within a detection surface in spite of 0th-order diffracted light included therein or to emit a light pattern for overall irradiation with a uniform light quantity distribution, without limiting a degree of freedom for design of the emitted light pattern. In a diffraction optical element according to the invention, a divergence angle converting function that is a function of converting the divergence angle of incident light due to diffraction effect and a light beam splitting function that is a function of splitting an incident light beam into a plurality of light beams due to diffraction effect are combined so that incident light as divergent light is split into a plurality of diffracted lights with different divergence angles from the divergence angle of the incident light and the diffracted lights is emitted.

Abstract: A security device including an array of lines printed or otherwise provided on a substrate, the lines including materials which have the same appearance under visible light illumination but which appear different from each other in the visible under a combination of visible and non-visible, ultraviolet illumination. At least some of the lines in the array appear different from other lines under the combination of visible and non-visible, ultraviolet illumination. A second, surface relief array of lines imposed on the first array, the orientation, line widths and spacings of the first and second arrays being such that the device exhibits a variable appearance as it is tilted while exposed to the combination of visible and non-visible illumination.

Abstract: The invention relates to a method for fabrication of a one-piece, silicon-based component of simple shape offering the illusion of faceting and/or chamfering for forming all or part of the exterior part of a timepiece.

Abstract: A reflective diffraction grating and a fabrication method are provided. The reflective diffraction grating includes a substrate, a UV-absorbing layer, a grating layer having a binary surface-relief pattern formed therein, and a conforming reflective layer. Advantageously, the UV-absorbing layer absorbs light at a UV recording wavelength to minimize reflection thereof by the substrate during holographic patterning at the UV recording wavelength.

Abstract: A display system comprises an optical waveguide, an actuator and a light engine. The light engine generates multiple input beams which form a virtual image. An incoupling grating of the optical waveguide couples each beam into an intermediate grating of the waveguide, in which that beam is guided onto multiple splitting regions. The intermediate grating splits that beam at the splitting regions to provide multiple substantially parallel versions of that beam. Those multiple versions are coupled into an exit grating of the waveguide, in which the multiple versions are guided onto multiple exit regions. The exit grating diffracts the multiple versions of that beam outwardly. The multiple input beams thus cause multiple exit beams to exit the waveguide which form a version of the virtual image. The actuator is coupled to the waveguide and is arranged to generate acoustic waves, which are incident on, and propagate through, the optical waveguide.