Facebook Technologies, LLC

Meta Platforms Technologies, LLC

Ningfeng Huang

Hee Yoon Lee

Pasi Saarikko

Giuseppe Calafiore

Wai Sze Tiffany Lam

Wanli Chi

Barry David Silverstein

Maxwell Parsons

Alexander Koshelev

Andrew John Ouderkirk

Lu Lu

Scott Charles McEldowney

Babak Amirsolaimani

Stephan Lutgen

Andrew Maimone

Yu Shi

Nihar Ranjan Mohanty

Gang Li

James Ronald Bonar

Gareth John Valentine

Yang Yang

Chloe Astrid Marie Fabien

David Massoubre

Dominic Meiser

Oleg Yaroshchuk

Heeyoon Lee

Francois Gerard Franck Olivier

Francois Olivier

Austin Lane

Erik Shipton

Siddharth Buddhiraju

Eric Fest

A pupil-replicating waveguide usable in a VR display may have a slab of transparent material, an input grating coupler supported by the slab at the center of the slab, with output gratings supported by the slab and surrounding the input grating coupler. The input grating coupler couples image light into the slab, which propagates in the slab by total internal reflections. The out-coupling grating or gratings spread the image light all around the input grating, providing a wide beam of image light illuminating the eyebox of the VR display.

Lightguide with radial pupil replication and visual display based thereon

A waveguide display includes a waveguide transparent to visible light, a first volume Bragg grating (VBG) on the waveguide and characterized by a first refractive index modulation, and a second reflection VBG on the waveguide and including a plurality of regions characterized by different respective refractive index modulations. The first reflection VBG is configured to diffract display light in a first wavelength range and a first field of view (FOV) range such that the display light in the first wavelength range and the first FOV range propagates in the waveguide through total internal reflection to the plurality of regions of the second reflection VBG. The plurality of regions of the second reflection VBG are configured to diffract the display light in different respective wavelength ranges within the first wavelength range and the first FOV range.

Spatially multiplexed volume Bragg gratings with varied refractive index modulations for waveguide display

A display system includes a wearable eyewear arrangement with a projector for propagating display light associated with an image and a waveguide for propagating the display light to an eye box. The waveguide includes volume Bragg gratings (VBGs), which may be in groups of three or more gratings with same horizontal period allowing each color to be coupled out from the waveguide by the same type of grating, thus, at the same angle, reducing or eliminating image blurriness and ghost images while allowing a smaller size waveguide. A 100% reflective mirror or mirror array is used for broad spectrum reflection into the waveguide for light input. Selection of two or more wavelengths for each color at the projector provides spectral response matching to the waveguide allowing wider field of view (FOV) coverage for the entire wavelength spectrum.

Multi-laser illuminated mixed waveguide display with volume Bragg grating (VBG) and mirror

A system includes one or more waveguides, and a plurality of grating sets coupled with the one or more waveguides. A plurality of combinations of gratings from the grating sets are configurable to direct an image light to propagate through a plurality of sub-eyeboxes forming an uncompressed eyebox. The system also includes a controller configured to selectively configure one or more combinations of gratings to operate in a diffraction state to direct the image light to propagate through one or more sub-eyeboxes forming a compressed eyebox having a size smaller than a size of the uncompressed eyebox.

Optical system and method for providing compressed eyebox

A waveguide assembly is provided. The waveguide assembly includes a pair of pupil-replicating waveguides. The first pupil-replicating waveguide is configured for receiving an input beam of image light and providing an intermediate beam comprising multiple offset portions of the input beam. The second pupil-replicating waveguide is configured for receiving the intermediate beam from the first pupil-replicating waveguide and providing an output beam comprising multiple offset portions of the intermediate beam. The input beam may be expanded by the waveguide assembly in such a manner that pupil gaps are reduced or eliminated.

Cascaded pupil-replicating waveguides

A diffraction grating includes a substrate and a plurality of fringes supported by the substrate. The fringes run parallel to each other in a first direction. A refractive index of a material of the plurality of fringes is anisotropic, whereby a refractive index contrast of the diffraction grating depends on direction of electric field of an impinging light beam, and through that dependence is a function of an azimuthal angle of the impinging light beam. A dependence of the diffraction efficiency on the azimuthal angle is affected by the dependence of the refractive index contrast on the direction of electric field of an impinging light beam. A pupil-replicating waveguide may use such a diffraction grating as a coupler for in- our out-coupling image light.

Anisotropic diffraction grating and waveguide

Techniques related to reclamation of energy leaking from waveguides are disclosed. One or more photovoltaic cells may receive light leaking from a waveguide at a first surface of the wave guide. The first surface may be opposite to a second surface at which an in-coupling element is located. The light leaking from the waveguide results from inefficiency in redirecting incoming light for propagation within the waveguide. The one or more photovoltaic cells may generate electric power from the light leaking from the waveguide.

Reclamation of energy leaking from waveguides

A waveguide display includes a display projector for emitting polychromatic image light, and a waveguide assembly for transmitting image light to an exit pupil. The waveguide assembly includes two or more waveguides disposed in a stack, each having an in-coupler aligned with the other in-couplers and an offset out-coupler aligned with the other out-couplers. The assembly is configured so that at least one color channel of the image light propagates to the exit pupil along at least two waveguides. A method for selecting the waveguides of the stack to suppress color channel splitting at the exit pupil is provided.

Display waveguide assembly with color cross-coupling

A color converter device includes an array of color conversion regions. The array of color conversion regions includes color conversion regions of a first type and color conversion regions of a second type that is distinct from the color conversion regions of the first type. A respective color conversion region of the array of color conversion regions includes a respective photonic crystal structure defining a respective two-dimensional pattern. The respective color conversion region includes a respective color conversion matrix. The color conversion regions of the first type converts light of a first color into light of a second color that is distinct from the first color and the color conversion regions of the second type converts the light of the first color into light of a third color that is distinct from the first color and the second color.

Directional color conversion using photonic crystals with quantum dots

A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of tapered slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. The tapered fringes result in the duty cycle of the diffraction grating varying along the thickness direction of the diffraction grating, to facilitate suppressing the portion of the display light out-coupled into the non-blazed diffraction order.

Outward coupling suppression in waveguide display

A method includes determining eye tracking information of an eye pupil. A method also includes selectively configuring, based on the eye tracking information, one or more combinations of gratings included in a plurality of grating sets coupled with one or more waveguides to operate in a diffraction state to direct an image light to propagate through one or more sub-eyeboxes of a plurality of sub-eyeboxes. The plurality of sub-eyeboxes define an uncompressed eyebox. The one or more sub-eyeboxes of the plurality of sub-eyeboxes define a compressed eyebox having a size smaller than a size of the uncompressed eyebox.

A pupil-replicating waveguide suitable for operation with a coherent light source is disclosed. A waveguide body has opposed surfaces for guiding a beam of image light. An out-coupling element is disposed in an optical path of the beam for out-coupling portions of the beam at a plurality of spaced apart locations along the optical path. Electrodes are coupled to at least a portion of the waveguide body for modulating an optical path length of the optical path of the beam to create time-varying phase delays between the portions of the beam out-coupled by the out-coupling element.

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Redmond, WA, United States of America

Ningfeng Huang