Abstract: A holographic display device accepts different configurations for rendering a Computer Generated Hologram. The decoder which prepares the CGH may not have the required memory and processing resources to provide the holographic display device with CGH generated in the nominal preferred configuration. According to the present principles, messages are exchanged between the holographic decoder and the holographic display device to select a configuration that the holographic display device accept and that fit the memory and processing resources of the holographic decoder.

Abstract: An optically-transparent device (100) is disclosed which comprises a main part (10) of dielectric material having a refractive index n2, said device being configured for forming a field intensity distribution in a near zone of said device from electromagnetic waves incidentally illuminating said device, when said device is embedded into a dielectric material having a refractive index n1 lower than said refractive index n2. Said device (100) further comprises at least one insert (11) of dielectric material having a refractive index n3 higher than said refractive index n2, said at least one insert being at least partly inserted into said main part, said refractive index n1 being different from said refractive index n3, and wherein Formula (I) with W2 being a half width of said insert and Formula (II), Formula (III) with W1 being a half width of said main part and Formula (IV), with ? being the wavelength of the electromagnetic wave propagating in the dielectric material having refractive index n1.

Abstract: An optical device and an eyeware apparatus comprising the optical device are disclosed. The optical device comprises a diffraction grating configured to diffract an incident light of a given wavelength on said optical device, said diffraction grating having a grating pitch above said given wavelength and being configured to diffract said incident light at a diffraction order having an absolute value equal to or greater than 2, wherein the optical device comprises an optical waveguide configured for guiding said light diffracted at a diffraction order having an absolute value equal to or greater than 2. The diffraction grating comprises a substrate of a first dielectric material with refractive index n3 and at least one second dielectric material with refractive index n2 deposited on said substrate, where n3<n2 or n3=n2.

Abstract: A device configured for radiating a focused electromagnetic beam is proposed. Such device comprises: —a first (101) and a second (102) part having respectively a second n2 and third n3 refractive index and a first W1 and second W2; —a first contact area (100e1) intended to be between a host medium having a first refractive index n1 and in which the micro or nanoparticles are intended to be trapped or moved by a focused electromagnetic beam radiated by the device; —a second contact area (100e2) between the first part and the second part; and —a third contact area (100e3) intended to be between the second part and the host medium. The focused electromagnetic beam results from a combination of at least two beams among a first (NJ1), a second (NJ2) and a third (NJ3) jet beams radiated respectively by the first, second and third contact areas when an incoming electromagnetic wave (IEM) illuminates the device.

Abstract: It is proposed an optical device for delivering a polychromatic image to an eye box being an area positioned in front of an eye of a user wearing said optical device. The optical device is remarkable in that it comprises: • a light-engine for delivering said polychromatic image, said light engine being able to generate n different monochromatic light image beams [C1, . . . , Ci, . . .

Abstract: An optical device forming an outgoing electromagnetic wave from an incident electromagnetic wave is disclosed. Such a device comprises at least one unit cell comprising:—at least two optical elements, an optical element being characterized by a type of optical response to said incident electromagnetic wave;—selection means enabling selective excitation of at least one optical element among the at least two optical elements, in response to said incident electromagnetic wave as a function of a wavelength of said incident electromagnetic wave, wherein said selection means comprise at one nanojet-based dielectric deflector compound of at least two dielectric material having different refractive indexes, and wherein said optical elements are placed at a distance from said nanojet-based dielectric deflector.

Abstract: In example embodiments. a waveguide apparatus is provided that may be used in a display device. The waveguide includes an in-coupler, an out-coupler, and at least a first eye-pupil expander along a first optical path from the in-coupler to the out-coupler. The in-coupler comprises a first diffraction grating and a second diffraction grating overlaying the first diffraction grating. wherein grating lines of the first and second diffraction gratings are parallel to one another. The first eye-pupil expander comprises a third diffraction grating and a fourth diffraction grating overlaying the third diffraction grating. The out-coupler comprises a fifth diffraction grating and a sixth diffraction grating overlaying the fifth diffraction grating.

Abstract: In example embodiments, an apparatus includes a waveguide having an in-coupler, an out-coupler, and at least one exit pupil expander along an optical path from the in-coupler to the out-coupler. A holographic optical element is provided on a surface of the waveguide substantially opposite the exit pupil expander. The holographic optical element being configured to selectively reflect light having a first characteristic and to selectively transmit light that does not have the first characteristic. The first characteristic may include light having an incident angle greater than a threshold angle, light having a propagation direction along the optical path from the in-coupler to the out-coupler, and/or light having a selected wavelength.

Abstract: In example embodiments, an apparatus includes a waveguide having an in-coupler an out-coupler. The waveguide has a first surface and an opposite second surface, and the waveguide provides at least one optical path from the in-coupler to the out-coupler. The in-coupler comprises a first diffraction grating with a first grating vector on the first surface and a second diffraction grating with a second grating vector on the second surface. At least one of the first and second grating vectors is not oriented along any of the optical paths from the in-coupler to the out-coupler. The second grating may alter the polarization state of in-coupled light and/or change the direction of the in-coupled light to aid in preventing the light from being out-coupled by the first diffraction grating.

Abstract: A device (200) is proposed comprising a first part (101) of a first material having a first refractive index n1 and a second part (102) of a second material having a second refractive index n2 higher than n1. Such device further comprises at least one contact area (110) in between the first and second parts, radiating an outgoing electromagnetic wave (100o) when the device is illuminated by an incoming electromagnetic wave (100i). A projection of the at least one contact area along a direction of propagation of the incoming electromagnetic wave has a non-vanishing height lower than 1.2 times a critical height equal to a wavelength in vacuum of the incoming electromagnetic wave divided by the difference between the second refractive index n2 and the first refractive index n1.

Abstract: The disclosure relates to an optically-transparent device (100) comprising a main part (10) of dielectric material having a refractive index n2. Such an optically-transparent device is configured for forming a field intensity distribution in a near zone of said device, from electromagnetic waves incidentally illuminating said device, when said device is embedded in a dielectric material having a refractive index n1 lower than said refractive index n2.

Abstract: Methods and apparatuses for encoding/decoding data content representative of a volumetric video are provided, wherein. the encoding/decoding comprises encoding in/decoding from a bitstream. an indicator specifying whether data content has information representative of at least one set of depth layers. the information representative of a set of depth layers specifying a number of depth layers and a depth value for each of the depth layers for a layer-based representation of the volumetric video. Methods and apparatuses for reconstructing Computer Generated Holograms from a reconstructed layered-based representation of the volumetric video are also provided.

Abstract: Embodiments include an optical system that may be included in a waveguide display. An example optical system includes a first waveguide having a first transmissive diffractive in-coupler (DG1) and a first diffractive out-coupler (DG6) and a second waveguide having a second transmissive diffractive in-coupler (DG2), a reflective diffractive in-coupler (DG3), a second diffractive out-coupler (DG4), and a third diffractive out-coupler (DG5). The second transmissive diffractive in-coupler (DG2) is arranged between the first transmissive diffractive in-coupler (DG1) and the reflective diffractive in-coupler (DG3) in an input region.

Abstract: Methods (1400) and apparatuses for encoding/decoding a sequence of multiple plane images representative of a 3D scene are provided, wherein the sequence of multiple plane images comprises at least one multiple plane image. a multiple plane image comprising a plurality of layers. said encoding comprising encoding in a bitstream. for at least one layer of the plurality of layers of the at least one multiple plane image. an indicator indicating whether the at least one layer has changed with respect to a corresponding layer of a reference multiple plane image, and encoding the at least one multiple plane image. Methods (1100) and apparatuses for reconstructing Computer Generated Holograms from the sequence of multiple plane images are also provided.

Abstract: In one embodiment of the disclosure, a diffraction grating structure is proposed comprising several grating lines. The diffraction grating structure is associated with a propagation layer, and the diffraction grating structure is made of a material that has a refractive index being equal to n2(?). The diffraction grating structure is remarkable in that it comprises T grating lines per ?m, with T=(n2(?)+1)/2?, where ? is a wavelength defined from an incident electromagnetic wave.

Abstract: In example embodiments, a waveguide display apparatus includes a waveguide comprising a substrate, a plurality of diffractive grating elements on the waveguide, and at least two coating layers on the waveguide between the substrate and the diffractive grating elements. The grating elements may be elements of a diffractive in-coupler. Some embodiments include three coating layers, with a middle layer having a refractive index greater than that of the substrate, the middle layer being between two layers having a refractive index lower than that of the substrate. Some embodiments further include a fourth coating layer.

Abstract: The present disclosure relates to an image sensor (21) comprising an array of pixels, wherein a set of pixels of the array comprises pixels with different height levels arranged according to their height level and relative position to an optical axis (22) of the image sensor, wherein each pixel of the set can take one height level i among N different height levels, N?2, where i=1 is the smallest height level and i=N is the highest height level. According to the disclosure, for a pixel of the set having a first height level equal to n, 2?n?N, and an adjacent pixel of the set having a second height level equal to m, lower than the first height level, in at least one of horizontal, vertical, or diagonal scanning direction, from a point at which the optical axis (22) intersects the image sensor (21) to at least one rim of the image sensor, the second height level m is equal to n?1.

Abstract: A method for reducing the parameters defining an acquired light field ray which enables only the colour associated with the light field ray to be stored instead of 4 light field co-ordinates (x,y,i,j) and its associated colour.

Abstract: Example embodiments include an optical system comprising a waveguide substrate. A diffractive coupler is associated with the waveguide substrate, the diffractive coupler comprising at least two diffraction gratings. Each of the diffraction gratings includes a first layer of grating elements and a second layer of grating elements, the first and second layers of grating elements being arranged in different planes. The first and second layers of grating elements each have a grating period associated with the respective diffraction grating, and the grating elements of the second layer have a lateral offset with respect to the grating elements of the first layer.

Abstract: Processing image information associated with a 3D scene can involve obtaining image data associated with at least one layer of the 3D scene; determining at least one phase increment distribution associated with the at least one layer for modifying at the at least one layer an image size associated with the scene; and determining a propagation of an image wave front, corresponding to the at least one layer, to a result layer at a distance from the scene to form a propagated image wave front at the result layer representing a hologram of the scene, wherein determining the propagation includes applying the at least one phase increment distribution associated with the at least one layer to the image wave front at the at least one layer.