Abstract: A system for measuring speckle contrast includes: a head up display (HUD) system configured to output a predetermined image and having a first pixels per degree (PPD); an imaging colorimeter: having a field of view; positioned such that the predetermined image is in the field of view; having a second PPD that is at least 2.2 times greater than the first PPD of the HUD system; and configured to capture an image including the predetermined image; and a speckle contrast module configured to determine a speckle contrast of the HUD system based on the image.

Abstract: Techniques related to generating holographic images are discussed. Such techniques include application of a machine learning model to the target image to generate data that is used to enable the determination of a phase pattern via a wave propagation model. The wave propagation model is used to generate holographic data, which is then adjusted according to one or more constraints associated with the holographic display that will be used to generate a holographic image based on the adjusted holographic data.

Abstract: A phase modulation structure includes a recording surface including phase angle recording regions in a plurality of calculated element regions corresponding to reconstruction points of an image on a one-to-one basis, each phase angle recording region being formed of a plurality of unit blocks in each of which a phase angle is recorded, the phase angle being calculated based on a phase that is a sum of a plurality of phases of light from the corresponding reconstruction points; and a representative area that is one of divisions of the calculated element region, the representative area being obtained by radially dividing the calculated element region centered on a point on the calculated element region, the point being obtained by extending a normal line from the corresponding reconstruction point to the calculated element region on the recording surface.

Abstract: A pseudo speckle pattern generation apparatus includes a light source, a beam expander, and a spatial light modulator. The spatial light modulator has an intensity modulation distribution based on a pseudo speckle pattern calculated from a pseudo random number pattern and a correlation function, receives light output from the light source and increased in beam diameter by the beam expander, spatially modulates the received light according to the modulation distribution, and outputs modulated light.

Abstract: A method of generating hologram data in a holographic display apparatus, including a hologram processing device generating hologram data and a display terminal reconstructing a hologram image in a three-dimensional (3D) space on the basis of the generated hologram data, includes generating depth map image data from input image data by using a deep learning engine for generating a depth map and calculating a complex value hologram on the basis of the depth map image data and the input image data to generate the hologram data.

Abstract: A method of producing a Computer Generated Hologram (CGH) for producing a 3 dimensional (3D) holographic image, including receiving data describing a 3D scene, producing a first CGH for producing a 2D image of the 3D scene as viewed from a specific viewing direction, the 2D image perpendicular to the viewing direction, decomposing the 2D image to a plurality of slices at different depths along the viewing direction, adjusting the first CGH by making, for at least one of the plurality of slices, a correction to the CGH associated with a depth of the slice along the viewing direction, thereby producing a corrected CGH for producing a 3D holographic image of the 3D scene. Related apparatus and methods are also described.

Abstract: A holographic display system for a motor vehicle includes a light source for generating a beam of coherent light and a spatial light modulator (SLM) having a two-dimensional pixel array. The two-dimensional pixel array modulates the beam of coherent light for generating a plurality of subframes, with each subframe being associated with one of a plurality of partial fields of view. The system further includes a scanner for directing the subframes onto associated sections of a display surface. The system further includes a computer having a memory including instructions, such that a processor is programmed to control the two-dimensional pixel array of the SLM for generating the subframes. The processor is further programmed to control the scanner for directing the subframes onto associated sections of the display surface and displaying a reconstructed image within a full field of view, which includes each of the partial fields of view.

Abstract: An optical device for forming a distribution of a three-dimensional light field comprises: an array of individually addressable unit cells; each unit cell in the array of unit cells comprising a stack including: at least one electrode; and a resonance defining layer, comprising at least a phase change material, PCM, layer, wherein the resonance defining layer is patterned to define a geometric structure dimensioned for defining a wavelength-dependent in-plane resonance of an electromagnetic wave; wherein the at least one electrode causes a phase change of the phase change material based on receiving a control signal to alter a wavelength-dependency of resonance in the resonance defining layer for controlling the optical property of the unit cell; wherein unit cells in the array of unit cells are separated such that the PCM layer of a unit cell is separated from the PCM layer in an adjacent unit cell.

Abstract: A light projection system comprising a light modulator that comprises a plurality of pixels each capable of selectively directing a corresponding modulatable amount of light, and a processor coupled to the light modulator to control the amount of light output from each of the plurality of pixels. The processor is configured to control the light modulator to form a computer generated hologram (CGH) wavefront from the light modulator corresponding to an image to be produced in the far field. The processor is also configured to control the light modulator to selectively direct the CGH wavefront. The light modulator may comprise an angular light modulator (ALM) comprising the plurality of pixels, each of the plurality of pixels having an OFF state and an ON state, the ALM arranged to direct the amounts of light in the direction as the pixels transition between the ON state and the OFF state.

Abstract: A display system comprising a first plurality of pixels, a second plurality of pixels, a first Fourier transform lens and a second Fourier transform lens. The first plurality of pixels is arranged ranged to display first holographic data corresponding to a first holographic reconstruction and receive light of a first wavelength. The a second plurality of pixels is arranged to display second holographic data corresponding to a second holographic reconstruction and receive light of a second wavelength. The first Fourier transform lens is arranged to receive spatially modulated light having a first wavelength from the first plurality of pixels and perform an optical Fourier transform of the received light to form the first holographic reconstruction at a replay plane, wherein the first holographic reconstruction is formed of light at the first wavelength.

Abstract: A holographic projector comprises an image processing engine arranged to, a hologram engine and a display engine. The image processing engine is arranged to receive a source image for projection. The source image comprises a first colour component and a second colour component. The image processing engine is further arranged to form a first colour secondary image from the first colour component by nulling alternate pixel values of the first colour component in accordance with a first checkerboard pattern. The image processing engine is further arranged to form a second colour secondary image from the second colour component by nulling alternate pixel values of the second colour component in accordance with a second checkerboard pattern. The first checkerboard pattern is opposite to the second checkerboard pattern.

Abstract: A volume hologram is arranged inside a transparent portion of a pane of a display device for a vehicle. The display device further includes a light source by which light is coupled into the volume hologram. An image appearing three-dimensional to a human observer can be generated by use of the volume hologram. A camera includes a light-sensitive image sensor to acquire images via an optical unit which is at least partially formed by the transparent portion of the pane.

Abstract: The present invention concerns an optical system for spatiotemporally shaping the wavefront of the electric field of a light beam (1) to be projected into a target volume (5), where the propagation axis is axis z, to create 3D patterned illumination in the target volume (5), comprising a pulsed laser source, configured to have an illumination pattern whose transversal surface at the target volume being superior to the diffraction limit of the optical system, at least one intermediate optical element (4) which is a dispersive grating for performing temporal focusing of the light beam (1), located, on the propagation axis (z), where an image of the illumination pattern is formed, for modulating the phase and/or the amplitude of the electric field of the light beam, and a second optical element (3) which is a spatiallight modulator for modulating the phase of the electric field of the input light beam, and for realizing spatiotemporal multiplexing to create 3D patterned illumination in the target volume (5) by r

Abstract: A method of reconstructing a three-dimensional (3-D) image on the basis of a diffraction grating includes extracting parallax images from a raw image of an object photographed by using a diffraction grating and reconstructing a 3-D image from the extracted parallax image array by using a virtual pinhole model.

Abstract: The disclosure provides in one aspect a head-up display for a vehicle. The head-up display comprises a picture generating unit, an optical system and a light-selective filter. The picture generating unit is arranged to display a picture on a screen. The optical system is arranged to receive light of the picture. The optical system comprises at least one optical element having optical power arranged to form a magnified image of the picture. The light-selective filter is transmissive to light of the picture and reflective to other light. The light-selective filter is disposed between the optical system and the screen. The light-selective filter has a first surface arranged to receive light from the optical system and a second surface arranged to receive light of the picture from the screen.

Abstract: A holographic projector comprises an image processing engine, a hologram engine, a display engine and a light source. The image processing engine is arranged to receive a source image for projection and generate a plurality of secondary images from the source image. The source image comprises pixels. Each secondary image comprises fewer pixels than the source image. A first secondary image has more pixels that a second secondary image. The hologram engine is arranged to determine, such as calculate, a hologram corresponding to each secondary image to form a plurality of holograms. Thus, a first hologram corresponding to the first secondary image has more pixels than a second hologram corresponding to the second secondary image. The display engine is arranged to display each hologram in turn on the display device. The light source is arranged to Illuminate each hologram during display to form a holographic reconstruction corresponding to each secondary image on a replay plane.

Abstract: A system for using free-space optics to interconnect a plurality of computing nodes can include a plurality of optical transceivers that facilitate free-space optical communications among the plurality of computing nodes. The system may ensure a line of sight between the plurality of computing nodes and the optical transceivers to facilitate the free-space optical communications. The line of sight may be preserved by the position or placement of the computing nodes in the system. The position or placement of the computing nodes may be achieved by using different shaped enclosures for holding the computing nodes.

Abstract: Method of laser modifying an optical fibre to form a modified region at a target location within the fibre, comprising positioning at least a portion of an optical fibre in a laser system for modification by a laser, applying a correction to an active optical element of the laser system to modify wavefront properties of the laser to counteract an effect of aberration on laser focus, and laser modifying the optical fibre at the target location using the laser with the corrected wavefront properties to produce the modified region.

Abstract: A wearable display device includes an optical device configured to form a virtual image, and a support device configured to support the optical device. The support device includes a first side support including a first temple, a second side support including a second temple, and a front frame extending between tip portions of the first side support and the second side support. The support device includes a flexible member between the tip portion of the first side support and a first end of the front frame and between the tip portion of the second side support and a second end of the front frame. The flexible members cause an interval between the tip portion of the first side support and the tip portion of the second side support to be changeable.

Abstract: A method for generating video holograms in real time for a holographic playback device comprising at least one light modulator means, into which a scene divided into object points is encoded as an entire hologram and can be seen as a reconstruction from a visibility region, which is located within a periodicity interval of the reconstruction of the video hologram, the visibility region defining a subhologram together with each object point of the scene to be reconstructed, and the entire hologram being generated from a superposition of contributions of subholograms, is characterized in that for each object point the contributions of the subholograms in the entire reconstruction of the scene can be determined from at least one look-up table.

Abstract: Techniques related to generating holographic images are discussed. Such techniques include application of a hybrid system including a pre-trained deep neural network and a subsequent iterative process using a sui table propagation model to generate diffraction pattern image data for a target holographic image such that the diffraction pattern image data is to generate a holographic image when implemented via a holographic display.

Abstract: A wearable display with coherent replication of optical beams is presented. The display includes a replication element comprising a plurality of features configured to receive and split impinging light into a plurality of sub-beams for propagation in a plurality of directions. At least a portion of the split sub-beams propagating in a direction of an eyebox of the NED form an image by optical interference.

Abstract: A holographic communication system and method can include: determining a user parameter for one or more users, generating a set of views based on the user parameter, and displaying the set of generated views.

Abstract: A hologram display device includes a light source unit that emits light, a spatial light modulator that modulates the light emitted from the light source unit, and a random pinhole panel. The random pinhole panel includes a plurality of pinholes of a random position or a random size and is arranged in line with an output part of the spatial light modulator. In the hologram display device and the method of manufacturing the hologram display device, a position and size of a random pinhole on the random pinhole are not limited to inside each pixel of the spatial light modulator.

Abstract: A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transforms these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

Abstract: Disclosed is a method for generating a digital hologram representing a 3D scene including an object, an object being defined by points and their associated intensity. For each object, a prior step of calculating an “omnidirectional” angular spectrum of the light field emitted by an object in the scene on the surface of a geometric solid centered on the object, a surface of the solid being sampled according to a predetermined grid, a sample of the grid being associated with a vector frequency; for the scene, the following steps: —obtaining a pose of an observer in the world frame of reference; —deriving the hologram from the scene as a function of the pose obtained from the “multidirectional” angular spectra calculated for each object. The step of calculating an angular spectrum of the light field for each object of the scene takes into account predetermined viewing directions.

Abstract: The projection device includes a light source, a liquid crystal on silicon (LCoS) panel, and a circuit. The circuit is configured to obtain a target image including a target pattern, and generate two content images. Each content image includes a duplicated pattern of the target pattern, and the duplicated patterns are off-axis shifted to the same coordinate when performing a computer-generated hologram (CGH) algorithm, so as to generate a phase image. The LCoS panel is driven according to the phase image to display a reconstructive image at a reconstructive distance.

Abstract: Provided are methods of processing a holographic image and apparatuses using the methods. A method includes obtaining image data with respect to a three-dimensional (3D) object, obtaining interference patterns in a computer-generated hologram (CGH) plane by performing a Fourier transform on the image data, and generating a CGH with respect to the 3D object based on the interference patterns, wherein the Fourier transform is performed based on a focal length of an eye lens of an observer.

Abstract: A method of generating three-dimensional (3D) shape information of an object to be measured from an image including intensity information of an object hologram generated by interference between a reference light reflected from an optical mirror and an object light affected by the object includes checking at least one frequency component included in the image and extracting real image components corresponding to a real image from the frequency component. The method also includes generating a correction light and a real image hologram based on the real image components, generating an intermediate hologram based on the correction light, and generating curvature aberration correction information from the intermediate hologram. The method further includes generating a correction hologram based on the curvature aberration correction information and generating the 3D shape information of the object from the correction hologram.

Abstract: A transparent holographic diffuser screen that diffracts the light beams of a digital light projector, which focuses a real image in the plane of the aforementioned transparent holographic diffuser screen, which redirects the light to an eyebox at a pre-determined viewing position generating as a set of diffracted diffused beams that can be seen from the eyebox as a flat in-plane image. The transparent holographic diffuser screen may be used to provide either a highest luminance or a largest eyebox. Potential applications include use for automotive applications, which may include applications for displaying videos, playing games, and video conference apps.

Abstract: A head worn imaging system includes a light source configured to generate a light beam. The system also includes a light guiding optical element having a thickness between 0.1 and 1.5 mm and configured to propagate at least a portion of the light beam by total internal reflection. The system further includes an entry portion and an exit portion of the light guiding optical element configured to selectively allow light addressing the exit portion to exit the light guiding optical element based on the angle of incidence of the light, the radius of curvature of the light and/or the wavelength of the light.

Abstract: An ultrasonic apparatus (100) for creating a holographic ultrasound field (1) comprises an ultrasound source device (10) being adapted for creating an ultrasound wave, and a transmission hologram device (20) having a transmission hologram (21) and an exposed acoustic emitter surface (22), said transmission hologram device (20) being acoustically coupled with the ultrasound source device (10) and being arranged for transmitting the ultrasound wave through the acoustic emitter surface (22) and creating the holographic ultrasound field in a surrounding space, wherein the acoustic emitter surface (22) is a smooth surface which do not influence the field distribution of the ultrasound wave. Furthermore, a method of creating a holographic ultrasound field in an object (3), wherein the ultrasonic apparatus (100) is used, and applications of the ultrasonic apparatus (100) are described.

Abstract: There is provided a spatial light modulator arranged to display a light modulation pattern including a hologram. The spatial light modulator includes a liquid crystal on silicon spatial light modulator having a plurality of pixels. The hologram has a plurality of pixels. The spatial light modulator includes a silicon backplane. Each pixel of the spatial light modulator includes a light-modulating element and a respective pixel circuit. Each pixel circuit is embedded in the silicon backplane. Each pixel circuit is arranged to drive the corresponding light-modulating element. Each pixel circuit is further arranged to combine a received pixel value of the hologram with a corresponding pixel value of the light processing function such that the light modulation pattern further includes the light processing function. The light processing function includes a lens function and/or a grating function.

Abstract: A head-up display for a vehicle, the head-up display including a picture generating unit arranged to generate a picture on a light receiving surface; and an optical system arranged to image the picture, where the optical system includes an input arranged to receive light of the picture; an output arranged to output light forming an image of the picture; a first mirror and second mirror arranged to guide light from the input to the output along an optical path, where the optical path includes a first optical path from the input to the second mirror including a transmission through the first mirror; and second optical path from the second mirror to the output including a reflection off the first mirror.

Abstract: There is provided a driver for a spatial light modulator. The spatial light modulator comprises [m×n] pixels. The driver is arranged to receive input holograms each comprising [x×y] pixels, wherein m?x and n?y. The driver is further arranged to drive the spatial light modulator to display thereon output holograms each comprising [m×n] pixels by tiling each input hologram onto the pixels of the spatial light modulator to form an output hologram corresponding to each input hologram using a tiling scheme. The driver is arranged to use a first tiling scheme to display a first output hologram and a second tiling scheme to display a second output hologram. Each output hologram comprises a plurality of tiles of the input hologram. Each tiling scheme defines the size of each tile and the position of each tile on the pixels of the spatial light modulator.

Abstract: Provided are on-axis and off-axis digital hologram generating device and method. The on-axis and off-axis digital hologram generating device includes an object phase generator configured to access a phase file of an object stored in a storage device and generate object phase information from the phase file of the object; a digital object light generator configured to generate digital object light information based on a light property of object light input by a user and the object phase information generated by the object phase generator; a digital reference light generator configured to generate digital reference light information based on a light property of reference light input by the user; and a digital hologram generator configured to generate a digital hologram based on hologram property information input by the user, the digital object light information generated by the digital object light generator, and the digital reference light information generated by the digital reference light generator.

Abstract: A system for lens-free imaging includes a processor in communication with a lens-free image sensor. The processor is programmed to operate the image sensor to obtain a hologram ??. The processor is further programmed to generate, from the hologram, a reconstructed image X and phase W at a focal depth z using an assumption of sparsity.

Abstract: A method and apparatus for processing hologram image data capable of optimizing image quality of a hologram image are provided. The image processing method includes receiving input image data, reading a header included at a predetermined location in the input image data, and generating hologram data configured to display a hologram image by performing a Fourier calculation and pixel encoding on the input image data based on at least one parameter recorded in the header, wherein the at least one parameter recorded in the header includes at least one of depth information, scale information, and gamma information.

Abstract: A three-dimensional (3D) image display apparatus is provided. The apparatus includes a plurality of light sources; a spatial light modulator configured to modulate light from the plurality of light sources according to 3D image information; and a focusing optical system configured to focus an image formed by the spatial light modulator onto a focal plane. The plurality of light sources may be arranged such that multiple focal points, respectively corresponding to the plurality of light sources, are formed on the focal plane near a pupil of a user.

Abstract: A method for digital holography includes modeling a hologram using a forward propagation model that models propagation of a light field from a hologram plane to an image plane. The method further includes computing the hologram as a solution to an optimization problem that is based on the model. The method further includes configuring at least one spatial light modulator using the hologram. The method further includes illuminating the spatial light modulator using a light source to create a target image.

Abstract: A laser apparatus comprising an aperture module array including two or more aperture modules, each aperture module of the array being optically couple-able to a source of coherent electromagnetic radiation and configured to emit a beam of radiation received from the source. The apparatus emits a composite beam comprising beams emitted by the respective aperture modules and modulates at least one of the beams in power and phase relative to at least one other of the beams such that a desired non-uniform composite beam profile is provided.

Abstract: An optical device includes a spatial light modulator and an optical waveguide with a plurality of extraction features. The plurality of extraction features is positioned relative to the optical waveguide so that a respective extraction feature receives light, having propagated within the optical waveguide, in a first direction and directs a first portion of the light in a second direction distinct from the first direction to exit the optical waveguide and illuminate at least a portion of the spatial light modulator. The plurality of extraction features is also positioned relative to the optical waveguide so that a respective extraction feature directs a second portion, distinct from the first portion, of the light to undergo total internal reflection, thereby continuing to propagate within the optical waveguide.

Abstract: Holographic and diffractive optical encoding techniques for forming reflection or transmission holograms. The encoding device includes a substrate having an interference pattern that can propagate light along a light propagation path from one side of the substrate to another side of the substrate. Furthermore, an optical element may be used to propagate light according to a four-dimensional light field coordinate system.

Abstract: Systems and methods are described that enable a 3D telepresence. In an exemplary method, a 3D image stream is generated of a first participant in a virtual meeting. A virtual meeting room is generated. The virtual meeting room includes a virtual window, and the 3D image stream is reconstructed in the virtual window. The first participant thus appears as a 3D presence within the virtual window. The virtual meeting room may also include virtual windows providing 3D views of other participants in the virtual meeting and may further include avatars of other meeting participants and/or of the first meeting participant.

Abstract: A holographic display system includes a light source that emits coherent light; a lateral displacement beam splitter that optically receives the coherent light and generates first reference light and second reference light; a first spatial light modulator (SLM) and a second SLM that optically receive the first reference light and the second reference light respectively, and construct first phase-only function (POF) light and second POF light respectively; a first beam splitter and a second beam splitter that optically receive the first POF light and the second POF light respectively, and generate first split light and second split light respectively; and a plurality of polarizers disposed between the first SLM and the first beam splitter, and between the second SLM and the second beam splitter, respectively.

Abstract: Methods and apparatus for forming a three-dimensional article in which a powdered medium is distributed in a powder bed, heated to a temperature below its melting point, and fused by means of a laser beam projected in the form of an image of a cross section of the three-dimensional article. The image of the cross-sectional layer is created by spatial light modulation of the laser beam using an LCoS display. During the fabrication process, characteristics of the image of the cross-sectional layer are controlled through monitoring of the projection of a holographic representation of the image using one or more imaging devices.

Abstract: A method to incorporate multiple independent optical correlators into one system. By “independent optical correlator,” we mean an optical correlator comprising of an input SLM, filter SLM, and camera, combined with appropriate coherent illumination and Fourier transforming lenses. By “one system” we mean a single optical system which utilises the elements of each of the independent correlators multiple times.

Abstract: An illuminating apparatus for a display screen with a transmissive image generator, having a free-viewing mode and a restricted-viewing mode, comprising a background illuminator radiating light in a wide angular range, a plate-shaped light guide in front of the background illuminator with outcoupling elements, and light sources. Outcoupling element dimensions are smaller than the width and height of subpixels of the image generator, parts of the surface of two outcoupling elements are below each subpixel and the filling factor of the outcoupling elements is maximally 50% of the large surface of the light guide, and at least 80% of the light coupled out is radiated within an angular range of 60°, and more than 50% of the light is radiated away from or toward the background illuminator, and in the restricted mode, the background illuminator and light sources are off, and in the free-viewing mode, the background illuminator is on.

Abstract: There is provided a method of projection using an optical element (502,602) having spatially variant optical power. The method comprises combining Fourier domain data representative of a 2D image with Fourier domain data having a first lensing effect (604a) to produce first holographic data. Light is spatially modulated (504,603a) with the first holographic data to form a first spatially modulated light beam. The first spatially modulated light beam is redirected using the optical element (502,602) by illuminating a first region (607) of the optical element (602) with the first spatially modulated beam. The first lensing effect (604a) compensates for the optical power of the optical element in the first region (607). Advantageous embodiments relate to a head-up display for a vehicle using the vehicle windscreen (502,602) as an optical element to redirect light to the viewer (505,609).

Abstract: Aspects of the technology provide a graphical display on a client device such as a smartwatch or other electronic display device. Content rendered by a non-emissive display element is augmented by an enhancement display element, for instance to change a color or illumination intensity of the content. The enhancement display element may include multiple illumination sources and light pipes that guide light from the light sources to specific regions along the display. Alternatively, the enhancement display element may be a transparent OLED or similar component, for instance to provide per-pixel illumination, highlighting and/or color enhancement to selected content items. In yet another configuration, the enhancement display element has a mask layer and a light element. The mask layer controls the amount of light reaching the non-emissive display element or viewable by a user. Each of these architectures provides rich enhancement to the content items generated by the non-emissive display element.