Abstract: An optical device with a variable index of refraction is formed by exposing a film to an energy gradient. The optical device has angular selectivity. The optical device can be used as an output coupler for a waveguide used in a virtual-reality and/or augmented-reality apparatus.

Abstract: An optical film fabrication method, an optical film and a head-mounted display are provided. The optical film fabrication method comprises: providing a substrate having a curved surface; dispensing a photo-alignment (PAM) layer on the curved surface of the substrate and exposing the PAM layer to spatially-uniformly polarized light; dispensing a birefringent material layer on the PAM layer; and curing the birefringent material layer to form a birefringent film on the curved surface. An optic axis orientation of birefringent material molecules in the birefringent film are spatially uniform across the birefringent film.

Abstract: An optical device with reduced see-through diffraction artifacts for Augmented Reality (AR) applications is provided. The device includes a projector configured to generate an image light and a waveguide optically coupled with the projector and configured to guide the image light to an eye-box. The waveguide includes an in-coupling element configured to couple the image light into the waveguide, and an out-coupling element configured to decouple the image light out of the waveguide. The waveguide includes at least one switchable grating configured to: during a virtual-world subframe of a display frame, decouple the image light out of the waveguide via diffraction, and during a real-world subframe of the display frame, transmit a light from a real-world environment to the eye-box with a diffraction efficiency less than a predetermined threshold.

Abstract: A near-eye display based on a polarization-selective diffusive combiner includes a polarizer for polarizing impinging ambient light to have a first polarization state, and a polarization-selective scatterer downstream of the polarizer, for passing through the ambient light having the first polarization state substantially without scattering, while scattering impinging display light having a second polarization state orthogonal to the first polarization state. The display light at the second polarization state may be provided by a projector, the polarization-selective scatterer playing the role of a projector screen. A polarization-selective ocular lens may be disposed downstream of the polarization-selective scatterer for viewing images generated by the projector while propagating through orthogonally polarized light from outside environment.

Abstract: A light-emitting disclosure (LED) and an LED array are disclosed. The LED includes a semiconductor junction for emitting light and an optical surface coupled to the semiconductor junction for outputting at least a portion of the light. The optical surface can include a grating structure configured to increase the portion of the light outputted by the optical surface, and/or a redirecting structure configured to redirect the portion of the light to form an output optical beam.

Abstract: A method includes providing frames of video data for being displayed by a head mounted display (HMD). Pixel data is encoded in a pixel of at least some of the video data frames, the encoded pixel data defining a focal state of an optics block of the HMD for displaying the respective frame of the video data to a user. The predetermined focal state is determined from a plurality of available focal states of the optics block, each focal state corresponding to a different focal plane of a virtual image generated based on the video data. The pixel used for encoding may be disposed outside a region of the frame that is displayable by the HMD.

Abstract: A method of notifying a user about attention from another user in an augmented reality/virtual reality (AR/VR) system is provided. The method includes displaying a first image on a first electronic display to a first user of the AR/VR system and, upon detecting a gaze of the first user at a second user of the AR/VR system or the second user's avatar in the first image, notifying the second user about the gaze of the first user by changing a parameter of an audio communication channel from the first user to the second user, so as to make the first user more audible to the second user.

Abstract: An optical waveguide is disclosed. The optical waveguide includes a plate of transparent material comprising opposed first and second surfaces for guiding an optical beam between the surfaces by at least one of reflection or diffraction. A diffraction grating is disposed at the first surface for spreading the optical beam by diffracting portions thereof into a non-zero diffraction order to propagate inside the plate. The first diffraction grating includes an array of parallel grooves structured to provide a spatial variation of optical phase of the portions of the optical beam diffracted by the first diffraction grating into the non-zero diffraction order.

Abstract: An apparatus for monitoring battery swelling includes a conductive layer adhered to a battery pack, a surface opposite the battery pack, a flex layer adhered to the bottom of the surface, and a resistance measurement circuit. The conductive layer includes one or more conductive strips. The flex layer includes a resistive pattern with one or more serially connected resistive segments. Each resistive segment is aligned to a respective conductive strip. The surface is positioned over the battery pack so that initially the resistive pattern is not in contact with and is electrically separated from the conductive layer. The resistance measurement circuit is connected to the resistive pattern to detect changes in resistance of the resistive pattern. When the battery pack swells, the resistive pattern comes in contact with the conductive layer, thereby shorting a resistive segment, and causes the resistance measurement circuit to detect the change in the resistance.

Abstract: Disclosed herein are techniques for fabricating straight or slanted variable-etch-depth gratings. A photoresist material for fabricating a variable-etch-depth grating in a substrate is sensitive to light with a wavelength shorter than 300 nm and has an etch rate comparable to the etch rate of the substrate. A depth of an exposed portion of a photoresist material layer including the photoresist material correlates with the exposure dose. After exposure using a gray-scale mask and development, the photoresist material layer has a non-uniform thickness. The photoresist material layer with the non-uniform thickness and the underlying substrate are etched using a straight etching or slanted etching process to form the straight or slanted variable-etch-depth grating in the substrate. The variable-etch-depth grating is characterized by a non-uniform depth profile corresponding to the non-uniform thickness of the photoresist material layer before etching.

Abstract: A method includes generating, by an illumination source, an optical beam and coupling the optical beam into an acousto-optic device. The acousto-optic device generates structured light from the coupled optical beam by diffracting the optical beam into at least two interfering optical beams. The interfering optical beams are then used to illuminate a surface of an eye of a user of a display for use in eye-tracking.

Abstract: A device includes a first optical element configured to receive first light in a first direction. The first light includes a first component having a first circular polarization and a second component having a second circular polarization. The first optical element is also configured to convert the first component of the first light into second light having the second circular polarization and output the second light in a second direction. The first optical element is further configured to convert the second component of the first light into third light having the first circular polarization and output the third light in a third direction. The device also includes a second optical configured to receive and transmit the second light and to receive the third light and convert to the third light into fourth light having the second circular polarization.

Abstract: An image sensor includes a two-dimensional array of active pixels, where each active pixel in the two-dimensional array of active pixels includes a respective photodiode. The image sensor also includes a plurality of lock-in pixels at two or more regions of the two-dimensional array. Each of the plurality of lock-in pixels includes two pixel elements that share a common photodiode. Each pixel element of the two pixel elements in a lock-in pixel includes a charge storage node and a switch configured to receive a respective control signal to selectively connect the respective charge storage node to the common photodiode.

Abstract: An optical assembly includes a first optical waveguide, a first in-coupler coupled with the first optical waveguide and a projector configured to project image light toward a first side of the first optical waveguide. The optical assembly also includes a first scanning reflector optically coupled with the projector and disposed on a second side of the first optical waveguide that is opposite to the first side. The projector is configured to project image light. The first scanning reflector is configured to receive the image light and to redirect the image light across a first range of directions. The first in-coupler is configured to redirect a first portion of the image light so that the first portion of the image light undergoes total internal reflection inside the first optical waveguide.

Abstract: Techniques are described for operating a display system comprising a light source and a scanning assembly. The light source includes a plurality of emitters arranged in a column and circuitry configured to drive the emitters based on image data. The scanning assembly includes a reflective surface facing the light source, the reflective surface being rotatable in at least one dimension. A control signal including periodic, non-linear pulses causes the reflective surface to rotate through a range of scan angles, thereby forming an output image based on reflection of emitted light. The image data is supplied to the light source in synchronization with the rotational movement of the reflective surface. Changes in rotation speed due to the non-linear nature of the control signal are compensated for by adjusting emission durations for different rows to provide different emission durations at different times based on changes in the linearity of the control signal.

Abstract: Techniques are disclosed for fabricating light-emitting structures in which recesses in a carrier adhesive layer are formed after singulation of the light-emitting structures. These recesses are self-aligned with the light-emitting structures and enable a pickup adhesive layer to be formed on each of the light-emitting structures without the need for creating an etching mask or etching the pickup adhesive layer.

Abstract: Disclosed herein are light emitting diodes (LEDs) having a high efficiency. A light emitting diode including an active light emitting layer within a semiconductor layer is provided. The semiconductor layer has a mesa shape. The light emitting diode also includes a substrate having a first surface on which the semiconductor layer is positioned and an outcoupling surface opposite to the first surface. Light generated by the active light emitting layer is incident on the outcoupling surface and propagates toward an optical element downstream of the outcoupling surface. The light emitting diode also includes a first anti-reflection coating adjacent to the outcoupling surface; an index-matched material between the outcoupling surface and the optical element, wherein an index of refraction of the index-matched material is greater than or equal to an index of refraction of the optical element; and/or secondary optics adjacent to the outcoupling surface.

Abstract: A display device includes a first display, a second display and one or more optical elements. The first display is configured to provide a first light that corresponds to a first image, the second display is configured to provide a second light that corresponds to a second image, and the one or more optical elements are configured to project a display image using the first light and the second light. The display image includes the first image and the second image. The display device is configured to project the first image with a first magnification and project the second image with a second magnification that is distinct from the first magnification. Also disclosed is a method performed by the display device.

Abstract: A light assembly can have an array of light sources forming rows and columns, where the array comprises a plurality of chips, and each chip comprises a subarray of light sources forming the rows and columns. A boundary between chips in the array can be configured to extend diagonally across rows and columns of the array such that, for each column across which the boundary extends, the first row of the plurality rows may not have a light source disposed in the respective column, but a second row of the plurality of rows has a light source disposed in the respective column.

Abstract: The present disclosure relates to systems, non-transitory computer-readable media, and methods for improving hand input detection in a virtual environment based on small and/or rapid hand inputs. For instance, a hybrid hand input detection system can utilize a hybrid hand input model that incorporates a machine-learning hand pose model with an optical flow network to recognize fine degrees of hand movement corresponding to input commands within a virtual environment. In this manner, the hybrid hand input detection system can utilize a hybrid hand input model to recognize small and rapid hand inputs in virtual reality or augmented reality without requiring a physical input device.