Abstract: Ion implantation is used to fabricate an optical device having a varying refractive index. The optical device can include a substrate with a material disposed on the substrate. A refractive index of the material is changed by ion implantation. The material can also be etched or imprinted. The optical device can be used in a virtual-reality system or augmented-reality system to provide angular selectivity from a display to a user's eye.

Abstract: An optical device is provided. The optical device includes an optical grating. The optical grating includes two electrodes arranged opposite to each other and a liquid crystal (LC) composition sandwiched between the electrodes. The two electrodes provide a driving voltage to the optical grating. The LC mixture includes a host LC and one or more LC dimers dissolved as a guest in the host LC. The host LC and the one or more LC dimers have respective dielectric anisotropies of opposite signs in nematic phase. A net dielectric anisotropy of the LC mixture is substantially neutral at a predetermined temperature.

Abstract: A near-eye display assembly includes an electronic display for providing image light, a circular polarizer disposed downstream of the electronic display for circularly polarizing the image light, and a pancake lens disposed downstream of the circular polarizer for conveying the image light to an eyebox of the near-eye display. The circular polarizer includes a quarter-wave waveplate disposed between the electronic display and the pancake lens, and spaced apart from the electronic display and the pancake lens, to additionally defocus ghost image artifacts at the eyebox.

Abstract: An optical system includes a grating including at least one substrate and a grating structure coupled to the at least one substrate. The grating structure is configured to diffract a first light having an incidence angle within a predetermined range. The optical system also includes a polarizer configured to transmit the first light diffracted by the grating structure and block a second light reflected by a surface of the at least one substrate.

Abstract: An artificial-reality device has a display with a plurality of pixels. In a calibration mode, the device determines gray-level values for the pixels using a uniform test image. Each pixel has a luminance level proportional to its gray-level value. The device groups the pixels into segments according to the luminance levels. For each of the segments, the device computes an overall luminance level and a luminance target according to the determined gray-level values. When the overall luminance level is below the luminance target for the segment, the device calculates calibration data, which either (i) increases the gray-level of each pixel in the segment by a specified amount or (ii) selects a gamma band for the segment corresponding to a difference between the luminance target and the overall luminance level. The device stores the calibration data. The device is configured to use the stored calibration data in subsequent display of images.

Abstract: A waveguide, e.g. an image-replicating waveguide, is provided. The waveguide includes a substrate having two outer surfaces, for propagating a beam of image light in the substrate by reflecting the beam from the outer surfaces. A diffraction grating is supported by the substrate and configured for diffracting the impinging beam. A partial reflector is disposed in the substrate between and parallel to the first and second surfaces. The partial reflector is configured for splitting the impinging beam, increasing the number of beam portions in the waveguide, thereby improving output pupil density.

Abstract: A transferrable thin-film optical device and a head-mounted display are provided. A transferrable thin-film optical device comprises a thin-film layer providing at least one predetermined optical function. The thin-film layer is configured to be removably attached to a substrate, such that a molecular pattern for the at least one predetermined optical function of the thin-film layer is preserved post removal.

Abstract: A varifocal liquid crystal lens in Alvarez configuration is disclosed. A head mounted or near-eye display may include a liquid crystal Alvarez lens for focus adjustment for user sight accommodation, vergence accommodation, etc. The liquid crystal Alvarez lens may be of various types, such as Pancharatnam-Berry phase (PBP) lens or a polarization volume holographic lens.

Abstract: A method is performed at a virtual-reality system that includes a head-mounted display (HMD) and a hand-held controller. The hand-held controller includes a grip, a user-input surface, and a tracking ring. the user-input surface includes a user-input key that is mounted on the grip, and the user input key includes an analog pressure sensor. The tracking ring is coupled to the user-input surface and the tracking ring includes a plurality of illumination sources on an outer surface of the tracking ring. The method displays an image of a hand on the HMD, and senses pressure applied to the analog pressure sensor by a user holding the hand-held controller and wearing the HMD. The method displays, on the HMD, the degree of closing the image of the hand in proportion to the pressure applied to the analog pressure sensor.

Abstract: A diffraction grating with independently controlled diffraction angles for optical beams at different wavelengths may be used to redirect and couple light to a waveguide in an efficient, space-saving manner. The diffraction grating can include a layer with optical permittivity and associated index contrast of the grating grooves at different grating periods dependent on wavelength.

Abstract: One embodiment of the present applications sets forth a wearable device that includes an interface layer configured to extend into an ear canal and a first audio emitter configuration coupled to the interface layer. The first audio emitter configuration is configured to produce a first plurality of soundwaves that are each directed towards a first point proximate to the first audio emitter configuration. The first plurality of soundwaves generates a first target soundwave that radiates in a first direction.

Abstract: A virtual-reality device includes a data generator, one or more processors, two or more gamma bands, and a display. The virtual-reality device generates initial color values for each of the plurality of pixels, and determines a respective gray-level value for each of the pixels according to the generated color values. The device selects, for each of the pixels, a respective gamma band corresponding to the determined respective gray-level value and one or more respective contextual markers, where each gamma band has a distinct luminance target. The virtual-reality device then adjusts the luminance level of each pixel according to the respective selected gamma band and displays the pixels according to the adjusted luminance levels.

Abstract: Disclosed herein are display systems and techniques for operating a display in a display system. An output image is formed by scanning a column of light emitters such that emitters in different rows of the column contribute to a same location in the output image. The emitters are driven using pulse-width modulation (PWM). PWM pulses are applied in synchronization with the scanning to cause emitters to emit light at an intensity corresponding to an illumination parameter. The driving includes generating, based on an illumination parameter, a PWM pulse by applying an analog signal in combination with applying a digital signal. The analog signal controls an amplitude of the PWM pulse. The digital signal controls a duration of the PWM pulse.

Abstract: A wearable display device and a calibration method for the wearable display device are provided. The wearable display device or its component(s) may exhibit optical throughput dependent on beam angle or beam coordinate at the eyebox. The linear or angular dependencies of throughput may be accounted for when generating an image to be displayed, to lessen or offset these dependencies during operation of the wearable display.

Abstract: Techniques for eye-tracking in a near-eye display system are disclosed. One example of a near-eye display system includes a waveguide-based display substrate transparent to visible light and configured to be placed in front of a user's eye. The waveguide-based display substrate includes a first light deflector configured to direct a first portion of invisible light reflected by the user's eye to a camera to form a first image of the user's eye in a first area of an image frame, and a second light deflector configured to direct a second portion of the invisible light reflected by the user's eye to the camera to form a second image of the user's eye in a second area of the image frame.

Abstract: A device and method are provided. The device comprises a reflector having variable optical power; and a waveguide display assembly optically coupled to the reflector and having a light source. The waveguide display assembly is configured to guide light from the light source to transmit in a first direction towards the reflector for a first optical path, and in a second direction towards an eye-box of the device for a second optical path. The reflector is configured to reflect the light in the first direction towards the eye-box.

Abstract: 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 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. A refractive index contrast profile of the diffraction grating along a thickness direction of the diffraction grating is symmetrical, and a refractive index contrast is larger at a middle than at both sides of the refractive index contrast profile, whereby the portion of the display light out-coupled into the non-blazed diffraction order is decreased.

Abstract: Methods and systems for reconstructing images from sensor data are provided. In one example, a method comprises: receiving input data generated by photodiodes each associated with a channel having a target wavelength range for photon-to-charge conversion; obtaining, for each channel, a plurality of channel coefficients, the plurality of channel coefficients being configured to, when combined with the input data to generate channel output data for the each channel, increase a main component of the channel output data contributed by a part of the incident light within the target wavelength range of the each channel with respect to a crosstalk component of the channel output data contributed by a part of the incident light out of the target wavelength range; and generating, for the each channel, the channel output data based on combining the input data with the plurality of channel coefficients to reconstruct an image for the each channel.

Abstract: A waveguide display includes a substrate having two opposite surfaces, and a slanted grating at a first surface of the two opposite surfaces of the substrate. The slanted grating includes a plurality of ridges and is characterized by a grating period in one direction. The plurality of ridges is tilted at a slant angle with respect to a surface normal of the first surface and is characterized by a height. The height of the plurality of ridges, the grating period, and the slant angle are configured to cause destructive interference between ambient light diffracted by the slanted grating. In some embodiments, a difference between the height of the plurality of ridges and an integer multiple of the grating period divided by the tangent of the slant angle is less than a threshold value.

Abstract: Techniques for eye-tracking in a near-eye display system are disclosed. One example of a near-eye display system includes a substrate transparent to visible light and configured to be placed in front of a user's eye, one or more light sources configured to emit illumination light invisible to the user's eye, one or more input couplers configured to couple the illumination light into the substrate, and one or more grating couplers each configured to couple a portion of the illumination light out of the substrate and towards the user's eye at a different direction. The illumination light coupled into the substrate propagates within the substrate through total internal reflection. The one or more grating couplers include at least one of a chirped surface-relief grating coupler or a volume Bragg grating coupler.