Abstract: A display cell of the subject technology includes two electrodes electrically coupled with a voltage supply, two alignment layers formed over surfaces of the two electrodes, and a liquid crystal (LC) material layer embedded between the two alignment layers. The alignment layers includes grooves and molecules of the LC material layer that are enabled to align along the grooves when no voltage is applied to the two electrodes. The two alignment layers include a polymer formed with a combination of an electron-donor monomer and an electron-acceptor monomer.

Abstract: An optical device includes a first electrode and a medium that includes ferroelectric liquid crystals and chiral dopants. The medium is located adjacent to the first electrode. The optical device may also include a second electrode distinct and separate from the first electrode. The optical device may be used as an optical dimming device, controlling an amount light passing through the optical device based on a voltage gradient provided to the optical device.

Abstract: An optical device includes a first set of one or more electrodes, a second set of one or more electrodes distinct and separate from the first set of one or more electrodes, and a solution containing transparent metal ions in a liquid or gel electrolyte. The solution is located between the first set of one or more electrodes and the second set of one or more electrodes. The optical device may operate as an optical dimming device, which may be used in head-mounted display devices or as dimmable windows or shutters.

Abstract: LED apparatuses and corresponding manufacturing techniques are described. In some examples, an LED apparatus includes a mesa etched from a layered epitaxial structure. The layered epitaxial structure includes a quantum well layer and a barrier layer adjacent to the quantum well layer. The barrier layer overhangs the quantum well layer as a result of the quantum well layer having been etched to a greater depth compared to the barrier layer. In some examples, the quantum well layer and the barrier layer are etched together to produce an area where the barrier layer overhangs the quantum well layer. Etching of the quantum well layer and the barrier layer can be performed after the layered epitaxial structure has been etched to form the mesa, in order to reduce surface imperfections leftover from the mesa etch. In some examples, one or more regrowth semiconductor layers are formed over etched facets of the mesa.

Abstract: A light source based on an optical frequency mixer is disclosed. The light source has a first laser for emitting light at a first optical frequency, and a plurality of second lasers for emitting light at different second optical frequencies. The optical frequency mixer provides output light beams at mixed optical frequencies of the first and second lasers. Wavelength of output light beams may be tuned by tuning wavelength of any of the first or second lasers. In this manner, RGB wavelength-tunable light sources may be constructed based on red or near-infrared lasers. The wavelength tunability of the output light beams may be used to angularly scan or refocus the light beams.

Abstract: A device includes a polarization rotator configured to be switchable between operating in two switching states. The device also includes a controller configured to control the polarization rotator to switch between operating in the two switching states at a predetermined switching frequency, to thereby switch, a polarization of a component of an input light having an initial light intensity, between two orthogonal polarizations at the predetermined switching frequency. The device also includes a polarizer coupled with the polarization rotator, and configured to convert the input light transmitted through the polarization rotator into an output light having a light intensity reduced to a predetermined percentage of the initial light intensity of the input light.

Abstract: The disclosed projector device may include (1) a first monochromatic emitter array having a plurality of emitters of a first color disposed in a two-dimensional configuration and (2) a second monochromatic emitter array having a plurality of emitters of a second color disposed in a two-dimensional configuration. The first and second monochromatic emitter arrays may be configured to emit images of the first and second colors into a waveguide configuration, and the first color may be different than the second color. Associated display systems and methods are also provided.

Abstract: The disclosed projector device may include (1) a first monochromatic emitter array having a plurality of emitters of a first color disposed in a two-dimensional configuration and (2) a second monochromatic emitter array having a plurality of emitters of a second color disposed in a two-dimensional configuration. The first and second monochromatic emitter arrays may be configured to emit images of the first and second colors into a waveguide configuration, and the first color may be different than the second color. Associated display systems and methods are also provided.

Abstract: LED apparatuses and corresponding manufacturing techniques are described. In some examples, an LED apparatus includes a mesa etched from a layered epitaxial structure. The layered epitaxial structure includes a quantum well layer and a barrier layer adjacent to the quantum well layer. The barrier layer overhangs the quantum well layer as a result of the quantum well layer having been etched to a greater depth compared to the barrier layer. In some examples, the quantum well layer and the barrier layer are etched together to produce an area where the barrier layer overhangs the quantum well layer. Etching of the quantum well layer and the barrier layer can be performed after the layered epitaxial structure has been etched to form the mesa, in order to reduce surface imperfections leftover from the mesa etch. In some examples, one or more regrowth semiconductor layers are formed over etched facets of the mesa.

Abstract: A visible light source includes a substrate, a vertical-cavity surface-emitting laser including an active semiconductor region configured to emit infrared light and a first reflector configured to reflect the infrared light emitted by the active semiconductor region, a second reflector configured to reflect the infrared light and form a vertical cavity for the infrared light with the first reflector, and one or more micro-resonators configured to receive the infrared light and generate visible light in one or more colors using the infrared light through optical parametric oscillation. The visible light source also includes one or more output couplers configured to couple the visible light in one or more colors from the one or more micro-resonators into free space or into a photonic integrated circuit.

Abstract: A visible light source includes a substrate, a first reflector and a second reflector configured to reflect infrared light and arranged vertically to form a vertical cavity on the substrate, an active region in the vertical cavity and configured to emit infrared light, a micro-resonator on the substrate and configured to receive the infrared light emitted by the active region and generate visible light through optical parametric oscillation, and an output coupler configured to couple the visible light generated in the micro-resonator out of the micro-resonator.

Abstract: The disclosed waveguide display device may include a waveguide and one or more projector assemblies configured to project image light into the waveguide, where each of the one or more projector assemblies includes a first monochromatic emitter array having a plurality of emitters of a first color disposed in a two-dimensional configuration and a second monochromatic emitter array having a plurality of emitters of a second color disposed in a two-dimensional configuration. The display device may also include at least one application specific integrated circuit (ASIC) configured to drive the first and second monochromatic emitter arrays to emit images of the first and second color along a common axis, with the first color being different from the second color. Various other devices, systems, and methods are also disclosed.

Abstract: 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.

Abstract: LED apparatuses featuring etched mesas and techniques for manufacturing LED apparatuses are described, including techniques for reducing surface recombination and techniques for charge carrier confinement. Etched facets of an LED mesa can be passivated using epitaxial regrowth of one or more semiconductor regrowth layers. The one or more semiconductor regrowth layers can include a transition layer. The transition layer can be configured with a bandgap energy between that of layers that are on opposite sides of the transition layer. A transition layer can separate an etched facet and another regrowth layer or separate two regrowth layers. In some instances, selective etching can be performed to preferentially etch a quantum well layer relative to a barrier layer. The selective etching removes surface imperfections, which contribute to surface recombination and which tend to be more prevalent in etched facets of the quantum well layer than etched facets of the barrier layer.

Abstract: A light source based on an optical frequency mixer is disclosed. The light source has a first laser for emitting light at a first optical frequency, and a plurality of second lasers for emitting light at different second optical frequencies. The optical frequency mixer provides output light beams at mixed optical frequencies of the first and second lasers. Wavelength of output light beams may be tuned by tuning wavelength of any of the first or second lasers. In this manner, RGB wavelength-tunable light sources may be constructed based on red or near-infrared lasers. The wavelength tunability of the output light beams may be used to angularly scan or refocus the light beams.

Abstract: Disclosed herein is an apparatus for providing conductivity. The apparatus may include an epitaxial layered structure having a first-type doped semiconductor layer, a second-type doped semiconductor layer, and an active layer between the first-type doped semiconductor layer and the second-type doped semiconductor layer. The apparatus may also include a conductive layer adjacent to and in ohmic contact with the first-type doped semiconductor layer. The conductive layer may have a micropixellated structure comprising a plurality of micropixel contact areas that are electrically isolated from each other. The plurality of micropixel contact areas may be sized and spaced to allow multiple ones of the plurality of micropixel contact areas to overlap a single contact pad for providing charge flow for a pixel in an array of pixels formed using the epitaxial layered structure.

Abstract: A device includes a polarization rotator configured to be switchable between operating in two switching states. The device also includes a controller configured to control the polarization rotator to switch between operating in the two switching states at a predetermined switching frequency, to thereby switch, a polarization of a component of an input light having an initial light intensity, between two orthogonal polarizations at the predetermined switching frequency. The device also includes a polarizer coupled with the polarization rotator, and configured to convert the input light transmitted through the polarization rotator into an output light having a light intensity reduced to a predetermined percentage of the initial light intensity of the input light.

Abstract: An optical dimming device includes at least one polarization rotator configured to switch a polarization of a linearly polarized component of an incoming light between two orthogonal polarizations. The optical dimming device also includes at least one polarizer coupled with the at least one polarization rotator, and configured to output a light having a light intensity reduced to a predetermined percentage of an initial light intensity of the incoming light. The predetermined percentage is substantially the same for different incoming lights having different initial polarizations.

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: In one embodiment, a computing system may receive a target color and a propagated error for a pixel location. The system may determine an error-modified target color for the pixel location based on the received target color and the propagated error. The system may identify, based on a location of the error-modified target color in a three-dimensional color space, a subset of pre-determined colors in the three-dimensional color space. The error-modified target color may correspond to a weighted combination of the subset of pre-determined colors. The system may determine a pixel color for the pixel location based on the subset of pre-determined colors and respective weights associated with the subset of pre-determined colors. The system may determine, based on the pixel color, driving signals for light-emitting elements associated with the pixel location. The system may output the driving signals to control the light-emitting elements associated with the pixel location.