Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for changing a distributed mode loudspeaker's fundamental frequency. One of the systems may include a light emitting diode display that includes an array of pixels, each pixel including, for each color of multiple colors, a directional light emitter and a wide-angle light emitter, a first combination of all the directional light emitters configured to generate a first display image viewable within a first viewing angle, and a second combination of all the wide-angle light emitters configured to generate a second display image concurrently with the generation of the first display image that is viewable within a second viewing angle. The first display image is a different image than the second display image and the first viewing angle is a narrower viewing angle than, and included within, the second viewing angle.

Abstract: A light field display for displaying a series of image frames to one or more viewers, the light field display includes: a plurality of light field pixels, each light field pixel including a plurality of light emitting elements, each light emitting element being configured to emit substantially collimated light, in which each light field pixel selectively emits light from each light emitting element into one or more of a plurality of different viewing directions during a single image frame during operation of the light field display; and an electronic controller in communication with the plurality of pixels, the electronic controller being programmed to cause each light field pixel to direct light into one or more of the plurality of different viewing directions such that a perspective of a displayed image varies according to the viewing direction.

Abstract: A light emitting device includes a substrate supporting a first light emitting element and a second light emitting element, the first light emitting element being configured to emit, in a first principal direction, light in a first wavelength band and the second light emitting element being configured to emit, in the first principal direction, light in a second wavelength band different from the first wavelength band, each light emitting element including: a light emitting diode layer, extending in a plane perpendicular to the first direction, having a thickness of 10 microns or less in the first direction and a maximum lateral dimension of 100 microns or less orthogonal to the first direction, the light emitting diode layer including a semiconductor material; and one or more layers configured to enhance an optical mode of the light emitted in the corresponding first or second wavelength band perpendicular to the plane and/or suppress an optical mode of the light emitted in the corresponding first or second w

Abstract: A process for producing a light emitting diode device, the process including: forming a plurality of quantum dots on a surface of a layer including a first area and a second area, the forming including: exposing the first area of the surface to light having a first wavelength while exposing the first area to a quantum dot forming environment that causes the quantum dots in the first area to form at a first growth rate while the quantum dots have a dimension less than a first threshold dimension; exposing the second area of the surface to light having a second wavelength while exposing the second area to the quantum dot forming environment that causes the quantum dots in the second area to form at a third growth rate while the quantum dots have a dimension less than a second threshold dimension; and processing the layer to form the LED device.

Abstract: A device includes a substrate (10) and a III-nitride structure (15) grown on the substrate, the III-nitride structure comprising a light emitting layer (16) disposed between an n-type region (14) and a p-type region (18). The substrate is a RA03 (MO)n where R is one of a trivalent cation: Sc, In, Y and a lanthanide; A is one of a trivalent cation: Fe (III), Ga and Al; M is one for a divalent cation: Mg, Mn, Fe (II), Co, Cu, Zn and Cd; and n is an integer?1. The substrate has an inplane lattice constant asubstrate. At lease one III-nitride layer in the III-nitride structure has a bulk lattice constant alayer such that [(|asubstrate?alayer|)/asubstrate]*100% is no more than 1%.

Abstract: A system and a method for determining local electric field strengths, the system including: a light source module configured to emit light; a plurality of electric field sensors, each sensor including a light input portion and a light output portion, each sensor including an electro-optic material arranged in a path of at least some of the received light, an optical property of the electro-optic material being variable depending on a local electric field strength at the sensor, and the electro-optic material being arranged in the sensor such that a property of the output light varies depending on the local electric field strength; a light detection module arranged to receive the output light from the sensors; and a processing module in communication with the light detection module, the processing module being programmed to determine a corresponding value for the electric field strength local to each of the sensors.

Abstract: An electro-optic (EO) sensor and a method for detecting a local electric field strength, the EO sensor including: a first optical cavity; a gain medium within the first optical cavity; a mode locking element within the first optical cavity; and an EO material within the first optical cavity, an effective optical path length of the EO material being variable depending on the local electric field strength at the EO sensor, wherein the gain medium, the mode locking element, and the EO material are arranged in a common path of light within the first optical cavity, and wherein during operation, the EO sensor emits pulses of light at a repetition rate characteristic of an effective optical path length of the light within the first optical cavity, the effective optical path length varying depending on the electric field strength local to the EO sensor.

Abstract: Methods and apparatus are described. An apparatus includes a hexagonal oxide substrate and a III-nitride semiconductor structure adjacent the hexagonal oxide substrate. The III-nitride semiconductor structure includes a light emitting layer between an n-type region and a p-type region. The hexagonal oxide substrate has an in-plane coefficient of thermal expansion (CTE) within 30% of a CTE of the III-nitride semiconductor structure.

Abstract: A process for producing a light emitting diode device, the process including: forming a plurality of quantum dots on a surface of a layer including a first area and a second area, the forming including: exposing the first area of the surface to light having a first wavelength while exposing the first area to a quantum dot forming environment that causes the quantum dots in the first area to form at a first growth rate while the quantum dots have a dimension less than a first threshold dimension; exposing the second area of the surface to light having a second wavelength while exposing the second area to the quantum dot forming environment that causes the quantum dots in the second area to form at a third growth rate while the quantum dots have a dimension less than a second threshold dimension; and processing the layer to form the LED device.

Abstract: An optical correlator includes a first spatial light modulator arranged to receive light from a light source and configured to selectively attenuate the light; a first focusing layer arranged to receive the selectively-attenuated light from the first spatial light modulator and configured to focus the selectively-attenuated light; a first spacer layer substantially transparent to the light from the light source, the first focusing layer being disposed on the first spacer layer; a second spatial light modulator arranged in a Fourier optical relationship with respect to the first spatial light modulator and configured to selectively attenuate the focused light from the first focusing layer to provide twice-attenuated light, the second spatial light modulator being disposed on the first spacer layer opposite the first focusing layer; a second spacer layer substantially transparent to the light from the light source, the second spatial light modulator being disposed on the second spacer layer and positioned betwe

Abstract: A device includes a first multi-element image sensor; a second multi-element image sensor; and a polarizing layer positioned between the first and second multi-element image sensors. A portion of light having a first polarization state incident on the device along a first direction is transmitted through the first image sensor, is transmitted through the polarizing layer, and is detected by the second image sensor, and light having a second polarization state orthogonal to the first polarization state incident on the device along the first direction is transmitted through the first image sensor, is blocked by the polarizing layer.

Abstract: In some implementations, a method includes receiving, by one or more processing devices configured to control a traffic signal at an intersection of roads, camera data providing images of the intersection, the processing devices being located proximate to the intersection, using one or more local machine learning models to identify objects at the intersection and paths of the objects based on the camera data, providing traffic data generated from outputs of the one or more local machine learning models to a remote traffic planning system over a network, receiving, from the remote traffic planning system, a remote instruction for the traffic signal determined using one or more remote machine learning models, and providing a control instruction to the traffic signal at the intersection that is determined based on (i) the remote instruction from the remote traffic planning system, and (ii) a local instruction generated by the processing devices.

Abstract: In a method according to embodiments of the invention, a III-nitride layer is grown on a growth substrate. The III-nitride layer is connected to a host substrate. The growth substrate is removed. The growth substrate is a non-III-nitride material. The growth substrate has an in-plane lattice constant asubstrate. The III-nitride layer has a bulk lattice constant alayer. In some embodiments, [(|asubstrate?alayer|)/asubstrate]*100% is no more than 1%.

Abstract: A laser device includes: a substrate formed from material transparent at a laser wavelength; a first reflecting layer to reflect at least some incident radiation at the laser wavelength; a layer including a gain medium for providing stimulated emission of radiation at the laser wavelength, and positioned between the first reflecting layer and the substrate; a second reflecting layer on an opposite side of the substrate from the first reflecting layer to reflect at least some incident radiation at the laser wavelength; a spatial light modulator in an optical cavity comprising the first and second reflecting layers, and comprising an array of elements each corresponding to a different path for radiation in the optical cavity; and a computer controller that, during operation, causes the spatial light modulator to selectively vary an intensity or phase of radiation in the optical cavity to provide variable transverse spatial mode output of the radiation.

Abstract: Methods and apparatus are described. An apparatus includes a hexagonal oxide substrate and a III-nitride semiconductor structure adjacent the hexagonal oxide substrate. The III-nitride semiconductor structure includes a light emitting layer between an n-type region and a p-type region. The hexagonal oxide substrate has an in-plane coefficient of thermal expansion (CTE) within 30% of a CTE of the III-nitride semiconductor structure.

Abstract: In a method according to embodiments of the invention, a III-nitride layer is grown on a growth substrate. The III-nitride layer is connected to a host substrate. The growth substrate is removed. The growth substrate is a non-III-nitride material. The growth substrate has an in-plane lattice constant asubstrate. The III-nitride layer has a bulk lattice constant alayer. In some embodiments, [(|asubstrate?alayer|)/asubstrate]*100% is no more than 1%.

Abstract: In embodiments of the invention, a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown on a substrate. The substrate is a non-III-nitride material. The substrate has an in-plane lattice constant asubstrate. At least one III-nitride layer in the semiconductor structure has a bulk lattice constant alayer and [(|asubstrate?alayer|)/asubstrate]*100% is no more than 1%. A surface of the substrate opposite the surface on which the semiconductor structure is grown is textured.

Abstract: In a method according to embodiments of the invention, a III-nitride layer is grown on a growth substrate. The III-nitride layer is connected to a host substrate. The growth substrate is removed. The growth substrate is a non-III-nitride material. The growth substrate has an in-plane lattice constant a substrate. The III-nitride layer has a bulk lattice constant a layer. In some embodiments, [(|a substrate?a layer|)/asubstrate]*100% is no more than 1%.

Abstract: In embodiments of the invention, a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown on a substrate. The substrate is a non-III-nitride material. The substrate has an in-plane lattice constant asubstrate. At least one III-nitride layer in the semiconductor structure has a bulk lattice constant alayer and [(|asubstrate?alayer|)/asubstrate]*100% is no more than 1%. A surface of the substrate opposite the surface on which the semiconductor structure is grown is textured.

Abstract: In embodiments of the invention, a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown on a substrate. The substrate is a non-III-nitride material. The substrate has an in-plane lattice constant asubstrate. At least one III-nitride layer in the semiconductor structure has a bulk lattice constant alayer and [(|asubstrate?alayer|)/asubstrate]100% is no more than 1%. A surface of the substrate opposite the surface on which the semiconductor structure is grown is textured.