Abstract: The invention relates to a waveguide display element comprising a waveguide body and an in-coupling grating (21) arranged to the waveguide body. The in-coupling grating (21) is configured to couple incoming light into the waveguide body into two separate directions (26A, 26B) using opposite diffraction orders (IC:+1, IC:?1) for splitting the field of view of the incoming light. Further the in-coupling grating (21) is configured, typically by setting its period suitably short, such that said coupling takes place only at wavelengths below a threshold wavelength residing in the visible wavelength range. The invention also relates to a waveguide stack (51 A, 51 B, 51 C).

Abstract: There is provided an exit pupil expander (EPE) for use in a diffractive display, the EPE comprising a plurality of diffractive zones on a waveguide and a plurality of non-diffractive zones between at least some of the diffractive zones.

Abstract: A diffractive waveguide element for a personal display device includes a display waveguide extending in a waveguide plane, an in-coupling diffractive optical element arranged onto or into the display waveguide for diffractively coupling light rays into the display waveguide, and an out-coupling diffractive optical element arranged onto or into the display waveguide for coupling the diffractively coupled light rays out of the display waveguide. In addition, there is provided a ray multiplier element optically upstream of the out-coupling diffractive optical element, the ray multiplier element being capable of splitting a light ray incoming to the in-coupling grating into a plurality of parallel rays spatially displaced in the waveguide plane before they enter the out-coupling diffractive optical element. A waveguide display device is also provided.

Abstract: The invention relates to a diffractive waveguide display device comprising an image projector capable of emitting laser rays at one or more wavelengths, a waveguide body having a first surface and an opposite second surface and adapted to guide said laser rays from the image projector between the first surface and the second surface, an out-coupling diffractive optical element on said first surface for coupling said laser rays out of the waveguide body, and an anti-interference coating (35) arranged on the second surface of the waveguide body aligned with the out-coupling diffractive optical element.

Abstract: This document discloses a solution for an optical waveguide for an augmented reality display device. According to an aspect, the optical waveguide comprises: a substrate arranged to guide an optical image inside the substrate from an inlet to an outlet of the optical waveguide via a plurality of reflections; a surface relief grating at the inlet or the outlet of the optical waveguide, the surface relief grating guiding the image in the optical waveguide via diffraction and comprising a plurality of grooves; a coating disposed on the surface relief grating and filling at least partially at least one groove disposed at an edge of the surface relief grating where the image is coincident with the at least one groove after a first reflection of the image inside the substrate, the coating having optical characteristics convergent with optical characteristics of the substrate.

Abstract: A lightguide of an augmented or virtual reality eyewear apparatus (10) comprises an additional grating (110) arranged between an in-coupling grating (102) and an out-coupling grating (104). The additional grating (110) comprises grating areas (112, 112?, 114, 114?), at least two of which have a common physical interface (116) and grating vectors of different directions. The grating vectors of the additional grating (110), the in-coupling grating (102) and the out-coupling grating (104) are linear combinations of two non-parallel and common base vectors, and a sum of the grating vectors of the in-coupling grating (102), the additional grating (110) and the out-coupling grating (104) is zero separately for each optical path, which guides light from the in-coupling grating (102) via the additional grating (110) to the out-coupling grating (104) and allows the light to be coupled out from the out-coupling grating (104).

Abstract: According to an example aspect of the present invention, there is provided an Exit Pupil Expander, EPE, grating which is divided into at least two segments, wherein the EPE grating comprises multiple grating bars in a first segment and multiple grating bars in a second segment, said multiple grating bars of the first segment being directed about to a same direction as said multiple grating bars of the second segment and misaligned in a direction which is perpendicular to the direction of the grating bars.

Abstract: A manufacturing method of an optical element (10) of an augmented reality eyewear. At least one layer (300) of a material (200) is deposited on a waveguide (106) through perforations (204) of a plate (202) at a non-zero distance (D) from the waveguide (106). Height of the at least one layer (300) is made to vary in response to cross sectional areas of the perforations (204), which vary based on a location of the perforations (204) in the plate (202) for forming at least one diffractive grating (100, 102, 104) on the waveguide (106) from the at least one layer (300), the at least one diffractive grating (100, 102, 104) performing in-coupling and/or out-coupling of visible light between the waveguide (106) and environment.

Abstract: The invention relates to a diffractive waveguide display element comprising a waveguide body (13) having a first surface and a second surface opposite to the first surface, an outcoupling-diffractive optical element on said first surface for coupling light propagating inside the waveguide body out of the waveguide body, and a narrow-band reflector element (21) on said second surface. The invention also relates to a display device comprising such element.

Abstract: There is provided a diffractive display element comprising a waveguide body, an in-coupling region for diffractively coupling light into the waveguide body, and an out-coupling region for diffractively coupling light out of the waveguide body, said light being adapted to propagate from said in-coupling region to the out-coupling region along a primary route. According to the invention, the element further comprises at least one grating mirror outside said primary route for diffractively mirroring light strayed from said primary route back to said primary route. The invention allows for increasing the efficiency of waveguide-based personal displays.

Abstract: The invention concerns a method of manufacturing a modulated optically diffractive grating and a corresponding grating. The method comprises providing a substrate and manufacturing a plurality of temporary elements onto the substrate, the temporary elements being arranged in a periodic pattern comprising at least two periods having different element characteristics. Next, a first deposition layer is deposited so as to at least partially cover the temporary elements with the first deposition layer and the temporary elements are removed from the substrate in order to form onto the substrate a modulated diffractive grating of first grating elements made of the first deposition layer, the pattern comprising within each period a plurality of first grating elements and one more gaps between the first grating elements. The invention allows for producing high-quality gratings with locally varying diffraction efficiency.

Abstract: The invention relates to a head-up display device, a vehicle comprising such device and a method of forming an image in a head-up display device. The head-up display device is adapted to project an image on an image surface, such as a windshield. The device comprises a waveguide capable of guiding light carrying the image to be displayed, and an optical correction element. According to the invention, the waveguide is configured to couple light propagating therein towards the optical correction element, and the optical correction element is further configured to perform an optical function for said light and to direct the light towards the image surface through the waveguide.

Abstract: The invention concerns a method of manufacturing a height-modulated optically diffractive grating. The method comprises providing a substrate and manufacturing a plurality of temporary elements of first material onto the substrate, the elements being separated by gaps and arranged as a periodic structure comprising at least two periods having different element heights. A coating layer of second material is deposited on the plurality of temporary elements such that the coating layer fills said gaps and covers said temporary elements. Then, a uniform layer of the second material is removed in order to expose said temporary elements and the first material is removed in order to form a height modulated pattern of the second material onto the substrate as the optically diffractive grating. The invention relaxes manufacturing constraints when manufacturing gratings with locally varying diffraction efficiency.

Abstract: The invention relates to a laser projector for presenting an image on a waveguide plane. The projector comprises a laser source (10, 10A, 10B, 10C) capable of emitting a polychromatic light beam (11) or a plurality of narrow-wavelength light beams (11A, 11B, 11C), and a guidance element (12A, 12B) for directing light emitted by the light source to different pupils (16A, 16B, 16C) of the waveguide plane, the different pupils being displaced with respect to each other in the waveguide plane. The invention also concerns a personal display device comprising such projector.

Abstract: The invention relates to a waveguide display element for guiding an image from a first lateral zone of the element to a second lateral zone of the element, the element comprising a plurality of waveguide layers (40A-E) on top of each other. The element further comprises at least one intermediate diffractive optical element (44AB, 44BC, 44AD, 44DE) arranged between two of said waveguide layers. The intermediate diffractive optical element (44AB, 44BC, 44AD, 44DE) is adapted to change the distribution of propagating light power between the layers. The invention also concerns a diffractive display device comprising such element.

Abstract: The invention concerns a multi-pupil lightguide element, a diffractive personal display, multi-pupil projector, a method for displaying an image and a use. The element comprises lightguide means, diffractive in-coupling means for coupling an image directed to the in-coupling means into the lightguide means, and diffractive out-coupling means for coupling said image out of the lightguide means. According to the invention, the diffractive in-coupling means comprise at least two in-coupling gratings laterally displaced from each other on said lightguide means for receiving segments of said image, and the diffractive out-coupling means is optically associated with said at least two in-coupling gratings for reproducing said image from said image segments. The invention allows for expanding the field-of-view of near-to-eye displays, for example.

Abstract: The invention relates to a method of fabricating a master plate for producing diffractive structures and a master plate obtainable therewith. The method comprises providing a substrate having a periodic surface profile, filling the surface profile uniformly at least partly with filling material, and partially removing the filling material in order to produce a master plate having a periodic height-modulated surface profile formed by said substrate and said filling material. The invention allows for producing master plates capable of further producing gratings with variable diffraction efficiency.

Abstract: The invention relates to a waveguide display element comprising a waveguide comprising at least three waveguide layers stacked on top of each other. There is also provided diffractive in-coupling gratings associated with each waveguide layer and being displaced with respect to each other in the plane of the layers, the in-coupling gratings forming input pupils for different light wavelength ranges coupled to the waveguide, and a diffractive out-coupling means for coupling light in-coupled through the pupils and propagating in the layers out of the waveguide such that a polychromatic image is formed. The invention also concerns a personal display device comprising such element.

Abstract: The invention concerns a diffractive waveguide element for a personal display device, the element comprising a waveguide body (21), and at least two grating regions (23, 24) arranged on the waveguide body (21), at least some of the grating regions adapted to expand the exit pupil of the element. According to the invention, the grating regions (23, 24) are positioned with respect to each other so that and are provided with gratings having different grating vectors so that the grating regions (23, 24) interact to combine the functions of exit pupil expansion and outcoupling on at least some parts of the element. The invention allows for efficient use of waveguide area.

Abstract: The invention provides a diffractive waveguide element, waveguide stack, personal display and method of forming a viewable image. The element comprises a waveguide region defined by two optical surfaces between which light can propagate by total internal reflections, the optical surfaces having surface profiles, and at least one diffractive grating capable of modifying the light filed within the waveguide region. According to the invention, the surface profile of at least one of said optical surfaces is a staircase profile.