Abstract: In an embodiment, a method involves accessing a first pixel block of an image, the first pixel block comprising pixels, each associated with three color values, determining whether to separately or jointly encode the three color values of each of the pixels of the first pixel block, determining that the three color values of each of the pixels in the first pixel block are to be jointly encoded based on (1) determining, based on the three color values of each of the pixels, a line defined within a three-dimensional coordinate system in which each of the pixels is represented as a three-dimensional point and (2) determining that the line satisfies a predetermined criteria, and encoding the three color values of each of the pixels in the first pixel block as a single quantized value based on a projection of the three-dimensional point associated with that pixel onto the line.

Abstract: An optical device is provided. The optical device includes a first optical element configured to output an elliptically polarized light having one or more predetermined polarization ellipse parameters. The optical device also includes a second optical element including a birefringent material with a chirality, and configured to receive the elliptically polarized light from the first optical element and reflect the elliptically polarized light as a circularly polarized light.

Abstract: The disclosed computer-implemented method may include identifying a muscle group engaged by a user to execute a predefined body action by (1) capturing a set of images of the user while the user executes the predefined body action, and (2) associating a feature of a body of the user with the muscle group based on the predefined body action and the set of images. The method may also include determining, based on the set of images, a set of parameters associated with the user, the muscle group, and the predefined body action. The method may also include directing a computer-generated avatar that represents the body of the user to produce the predefined body action in accordance with the set of parameters. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: This disclosure describes techniques that include modifying text associated with a sequence of images or a video sequence to thereby generate new text and overlaying the new text as captions in the video sequence. In one example, this disclosure describes a method that includes receiving a sequence of images associated with a scene occurring over a time period; receiving audio data of speech uttered during the time period; transcribing into text the audio data of the speech, wherein the text includes a sequence of original words; associating a timestamp with each of the original words during the time period; generating, responsive to input, a sequence of new words; and generating a new sequence of images by overlaying each of the new words on one or more of the images.

Abstract: A manufacturing system for creating waveguides that include optical gratings having high coupling efficiencies is described herein. The waveguides are used to guide image light from a source assembly to an eye of a user. The optical gratings are used to couple light into an optical waveguide element and/or decouple light from the optical waveguide element. The manufacturing system creates optical gratings by patterning and adjusts refractive indexes of the optical gratings by infusion and post-processing. A refractive index of an optical grating can be uniform or non-uniform. In-coupling efficiencies of light into a waveguide via the optical gratings and/or out-coupling efficiencies of light out of a waveguide via the optical gratings can be increased. The manufacturing system includes a patterning system, an infusion system, and a post-processing system.

Abstract: Embodiments relate to a method of fabricating a nano-sized structure in a resin element by nanoimprint lithography (NIL). The method reduces adhesive failure during NIL demolding by inhibiting polymerization at the interface between the resin element and the template. The method includes depositing a layer of polymerization inhibiting compound onto a surface of the template. The layer of polymerization inhibiting compound has a thickness no more than 10 nanometers. A surface of the template has a nano-sized pattern that mirrors that nano-sized structure. The method further includes pressing the template onto the resin element (or the resin element onto the template) to form the nano-sized structure in the resin element. The process also includes curing the resin element after forming the nano-sized structure and removing the template from the resin element after curing the resin element. The polymerization inhibiting compound prevents adhesive failure during the removing.

Abstract: The disclosed structured light projector may include (1) a light source having a light-emitting side that emits light, (2) a solid optical spacer element having a first side securely coupled to the light-emitting side of the light source, and (3) a diffractive optical element (DOE) stack including one or more DOEs, where the DOE stack includes (a) a light-receiving side securely coupled to a second side of the solid optical spacer element opposite the first side, and (b) a light-emitting side opposite the light-receiving side that emits structured light in response to the light received from the light-emitting side of the light source via the solid optical spacer element. Various other devices and methods are also disclosed.

Abstract: This disclosure describes systems on a chip (SOCs) that prevent side channel attacks (SCAs). An example SoC of this disclosure includes an engine configured to encrypt transmission (Tx) channel data using an encryption operation set configured with a first polynomial, and to decrypt encrypted received (Rx) channel data using a decryption operation set configured with a second polynomial different from the first polynomial. The SoC further includes a security processor configured to multiplex the encryption operation set against the decryption operation set with a varied sequence of selection inputs on a round-by-round basis to generate a mixed sequence of encryption rounds and decryption rounds, and to control the engine to encrypt the Tx channel data and decrypt the encrypted Rx channel data in a combined datapath according to the mixed sequence of encryption rounds and decryption rounds.

Abstract: A liquid crystal (LC) mixture for a pitch variable optical element is provided. 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.

Abstract: The disclosed liquid lens array may include a plurality of independently operable array sections, each of which may include (1) a transparent base layer, (2) an aperture plate overlapping the transparent base layer, the aperture plate defining a plurality of apertures extending through the aperture plate between an inner surface of the aperture plate facing the transparent base layer and an outer surface of the aperture plate, and (3) a liquid reservoir disposed between the base layer and the aperture plate. The liquid lens array may also include driving circuit for operating at least one array section of the plurality of array sections to change liquid volumes extending from the liquid reservoir at least partially through the apertures defined in the aperture plate of the at least one array section. Various other methods, systems, and devices are also disclosed.

Abstract: A depth camera assembly (DCA) for depth sensing of a local area. The DCA includes a transmitter, a receiver, and a controller. The transmitter illuminates a local area with outgoing light in accordance with emission instructions. The transmitter includes a fine steering element and a coarse steering element. The fine steering element deflects one or more optical beams at a first deflection angle to generate one or more first order deflected scanning beams. The coarse steering element deflects the one or more first order deflected scanning beams at a second deflection angle to generate the outgoing light projected into the local area. The receiver captures one or more images of the local area including portions of the outgoing light reflected from the local area. The controller determines depth information for one or more objects in the local area based in part on the captured one or more images.

Abstract: A display device includes a display panel having a first emission region and one or more second emission regions disposed adjacent to the first emission region. The display device includes a plurality of light emitters, arranged in the first emission region, corresponding to a first color gamut and a plurality of light emitters, arranged in the one or more second emission regions, corresponding to a second color gamut that is distinct from the first color gamut. A method for making a display device with a plurality of light emitters corresponding to a first color gamut in a first emission region and a plurality of light emitters corresponding to a second color gamut in a second emission region is also described.

Abstract: The disclosure describes artificial reality (AR) systems and techniques that enable secure, privacy-preserving device attestation and mutual authentication of multiple devices used concurrently within a multi-device AR system. For example, an AR system comprises a security server configured to generate a pairing certificate that includes information identifying a plurality of devices to be operationally paired with each other. The AR system comprises a peripheral device configured to receive one or more inputs from a user of the AR system, wherein the peripheral device is configured to store the pairing certificate in a non-volatile memory (NVM) of the peripheral device for authenticating the peripheral device and a head-mounted display (HMD) for pairing. The AR system comprises the HMD configured to output artificial reality content, wherein the HMD is configured to store the pairing certificate in a NVM of the HMD for authenticating the HMD device and the peripheral device for pairing.

Abstract: A device includes a plurality of first LEDs, a plurality of second LEDs, at least one controllable current source that is configured to generate at least one bias current for driving the plurality of first LEDs and the plurality of second LEDs, and a plurality of measurement circuits, each of which is configured to measure a current-voltage (I-V) performance characteristic of at least one of the plurality of first LEDs. A property of a first bias current of the at least one bias current is determined as a function of at least two measurements of the I-V performance characteristic of the at least one of the plurality of first LEDs, and the at least two measurements of the I-V performance characteristic are acquired while the first bias current is applied to the at least one of the plurality of first LEDs and the plurality of second LEDs.

Abstract: Disclosed herein are systems and methods related to describing slot information. In one aspect, a first wireless communication device determines a bitmap having a value for each of a plurality of slots for wireless traffic. The bitmap may indicate a status or type of a corresponding slot. The first wireless communication device may send, using a wireless local area network (WLAN) based protocol, to a second wireless communication device, a message comprising the bitmap. The message may further comprise a duration of each of the plurality of slots, a period of the plurality of slots, and a persistency of the plurality of slots.

Abstract: An optical system includes an optical waveguide, and a first optical element configured to direct a first ray, having a first circular polarization and impinging on the first optical element at a first incidence angle, in a first direction so that the first ray propagates through the optical waveguide via total internal reflection toward a second optical element. The first optical element is configured to also direct a second ray, having a second circular polarization that is distinct from the first circular polarization and impinging on the first optical element at the first incidence angle, in a second direction that is distinct from the first direction so that the second ray propagates away from the second optical element. The second optical element is configured to direct the first ray propagating through the optical waveguide toward a detector.

Abstract: A light emitting diode (LED) chip is bonded to a substrate. The LED chip includes a plurality of electrodes that each corresponds to a contact on the substrate. The plurality of electrodes are exposed to one or more laser beams for coupling the LED chip to the substrate. The laser beams may be directed to one or more edges or corners of the plurality of electrodes, where the edges or corners lie outside emission areas of LEDs on the LED chip.

Abstract: A system for making a holographic medium for use in generating light patterns for eye tracking includes a light source configured to provide light and a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light. The system also includes a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium, a second set of optical elements configured to transmit the second portion of the light for providing a second wide-field beam, and a plurality of parabolic reflectors optically coupled with the second set of optical elements and configured to receive the second wide-field beam and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium.