Abstract: A structure and method of operating an optical step-up transformer are described. The optical step-up transformer has at least one photodiode and at least one photoreceiver. The photoreceiver receives light emitted from the photodiode and generates a voltage proportional to the number of series-connected photoreceivers. The photodiode and photoreceiver may be electrically isolated or may share a common anode or cathode. The voltage applied to the photodiode may be a DC or PWM signal.

Abstract: LED arrays comprise patterned reflective grids that enhance the contrast ratio between adjacent pixels or adjacent groups of pixels in the array. The pattern on the reflective grid may also improve adhesion between the reflective grid and one or more layers of material disposed on and attached to the reflective grid. The reflective grid may be formed, for example, as a reflective metal grid, a grid of dielectric reflectors, or a grid of distributed Bragg reflectors (DBRs). If formed as a metal grid, the reflective grid may provide electrical contact to one side of the LED diode junctions. This specification also discloses fabrication processes for such LED arrays.

Abstract: A gas sensing system can allow a gas sample to permeate hollow spaces within a porous scattering material. The porous scattering material can be substantially transparent at an illumination wavelength. An emitter can illuminate the porous scattering material and the gas sample with light having a spectrum that includes the illumination wavelength. A sensor can detect a level of light that has traversed the porous scattering material. Using, for example, the Beer-Lambert Law, the system can determine a concentration of the gas material in the gas sample. The scattering can greatly increase an optical path length through the porous scattering material, compared with a linear dimension of the porous scattering material. The increased optical path length can allow a gas chamber to shrink in size, thereby decreasing a size of the gas sensing system without a corresponding decrease in a sensitivity and/or an accuracy of the system.

Abstract: A light-emitting apparatus includes light-emitting and primary optics arrays. The light-emitting array includes multiple light-emitting pixel elements, each emitting at one of one or more output wavelengths. The primary optics array includes multiple metastructured primary optical elements, each receiving output light from a corresponding pixel element and redirecting that light to form a portion of array output light. Different primary optical elements receive pixel output light from different corresponding pixel elements. The primary optical elements differ from one another with respect to structural arrangement of their corresponding metastructures. Those different arrangements result in differing collimation, propagation directions, or angular radiation distributions of the corresponding portions of array output light emitted by different pixel elements of the light-emitting array.

Abstract: In a method according to embodiments of the invention, for a predetermined amount of light produced by a light emitting diode and converted by a phosphor layer comprising a host material and a dopant, and for a predetermined maximum reduction in efficiency of the phosphor at increasing excitation density, a maximum dopant concentration of the phosphor layer is selected.

Abstract: In a gas sensing system, a light emitter can emit light through a gas sample toward a concave reflective surface. The reflective surface can redirect the emitted light to propagate through the gas sample toward a light sensor. Using, optionally, the Beer-Lambert Law, the system can determine a concentration of the gas material in the gas sample. By selecting a specified shape for the reflective surface, such as a complete or partial ellipsoid, and locating the light emitter and the light sensor in specified locations, such as at one or both foci of the ellipsoid, the gas sensing system can reduce variation in optical path length, from optical path to optical path, in the light that propagates from the light emitter, to the reflective surface, and to the light sensor. Reducing the variation in optical path length can improve an accuracy in determining the concentration of the gas material.

Abstract: In a gas sensing system, an emitter emits light through a gas toward a concave reflective surface. The reflective surface reflects the light toward a sensor while light that passes through a porous scattering material is scattered. The surface of the reflective surface provides a diffusion of the light. A concentration of the gas is detected by the sensor. The scattering material may be permeable or non-permeable to the gas. The scattering and reflecting of the light increases the distance the light travels from the emitter to the sensor to increase absorption of the light by the gas.

Abstract: A structure and method of micro-LEDs are described. The micro-LEDs have a GaN semiconductor structure containing a multi-quantum well active region configured to emit light of a visible wavelength range and a multilayer reflector structure that includes a distributed Bragg reflector (DBR) with a maximum reflectance at the visible wavelength range and to reflect the light emitted by the active region towards an emission surface of the semiconductor structure. The multilayer reflector structure also has a protective layer between the DBR and the GaN structure that is transparent to light of visible wavelengths. The multilayer reflector structure also has an absorbing metal layer that absorbs the light of visible wavelengths. A conductive material provides electrically contact to the semiconductor structure.

Abstract: LED arrays comprise patterned reflective grids that enhance the contrast ratio between adjacent pixels or adjacent groups of pixels in the array. The pattern on the reflective grid may also improve adhesion between the reflective grid and one or more layers of material disposed on and attached to the reflective grid. The reflective grid may be formed, for example, as a reflective metal grid, a grid of dielectric reflectors, or a grid of distributed Bragg reflectors (DBRs). If formed as a metal grid, the reflective grid may provide electrical contact to one side of the LED diode junctions. This specification also discloses fabrication processes for such LED arrays.

Abstract: An optical isolation material may be applied to walls of a first cavity and a second cavity in a wafer mesh. A wavelength converting layer may be deposited into the first cavity to create a first segment and into the second cavity to create a second segment. The first segment may be attached to a first light emitting device to create a first pixel and the second segment to a second light emitting device to create a second pixel. The wafer mesh may be removed.

Abstract: Pre-formed wavelength conversion elements are attached to light emitting elements and are shaped to reduce repeated occurrences of total internal reflection. The sides of the shaped elements may be sloped or otherwise shaped so as to introduce a change in the angle of incidence of reflected light upon the light extraction surface of the wavelength conversion element. The pre-formed wavelength conversion elements may be configured to extend over an array of light emitting elements, with features between the light emitting elements that are shaped to reduce repeated occurrences of total internal reflection.

Abstract: Embodiments of the invention include a semiconductor light emitting device capable of emitting first light having a first peak wavelength and a semiconductor wavelength converting element capable of absorbing the first light and emitting second light having a second peak wavelength. The semiconductor wavelength converting element is attached to a support and disposed in a path of light emitted by the semiconductor light emitting device. The semiconductor wavelength converting element is patterned to include at least two first regions of semiconductor wavelength converting material and at least one second region without semiconductor wavelength converting material disposed between the at least two first regions.

Abstract: A gas sensing system can allow a gas sample to permeate hollow spaces within a porous scattering material. The porous scattering material can be substantially transparent at an illumination wavelength. An emitter can illuminate the porous scattering material and the gas sample with light having a spectrum that includes the illumination wavelength. A sensor can detect a level of light that has traversed the porous scattering material. Using, for example, the Beer-Lambert Law, the system can determine a concentration of the gas material in the gas sample. The scattering can greatly increase an optical path length through the porous scattering material, compared with a linear dimension of the porous scattering material. The increased optical path length can allow a gas chamber to shrink in size, thereby decreasing a size of the gas sensing system without a corresponding decrease in a sensitivity and/or an accuracy of the system.

Abstract: In a gas sensing system, a light emitter can emit light through a gas sample toward a concave reflective surface. The reflective surface can redirect the emitted light to propagate through the gas sample toward a light sensor. Using, optionally, the Beer-Lambert Law, the system can determine a concentration of the gas material in the gas sample. By selecting a specified shape for the reflective surface, such as a complete or partial ellipsoid, and locating the light emitter and the light sensor in specified locations, such as at one or both foci of the ellipsoid, the gas sensing system can reduce variation in optical path length, from optical path to optical path, in the light that propagates from the light emitter, to the reflective surface, and to the light sensor. Reducing the variation in optical path length can improve an accuracy in determining the concentration of the gas material.

Abstract: An LED module includes a substrate having a high thermal conductivity and at least one LED die mounted on the substrate. A wavelength conversion material, such as phosphor or quantum dots in a binder, has a very low thermal conductivity and is formed to have a relatively high volume and low concentration over the LED die so that the phosphor or quantum dots conduct little heat from the LED die. A transparent top plate, having a high thermal conductivity, is positioned over the wavelength conversion material, and a hermetic seal is formed between the top plate and the substrate surrounding the wavelength conversion material. The LED die is located in a cavity in either the substrate or the top plate. In this way, the temperature of the wavelength conversion material is kept well below the temperature of the LED die. The sealing is done in a wafer level process.

Abstract: Embodiments of the invention include a light emitting device, a first wavelength converting material, and a second wavelength converting material. The first wavelength converting material includes a nanostructured wavelength converting material. The nanostructured wavelength converting material includes particles having at least one dimension that is no more than 100 nm in length. The first wavelength converting material is spaced apart from the light emitting device.

Abstract: In a method according to embodiments of the invention, for a predetermined amount of light produced by a light emitting diode and converted by a phosphor layer comprising a host material and a dopant, and for a predetermined maximum reduction in efficiency of the phosphor at increasing excitation density, a maximum dopant concentration of the phosphor layer is selected.

Abstract: In a method according to embodiments of the invention, for a predetermined amount of light produced by a light emitting diode and converted by a phosphor layer comprising a host material and a dopant, and for a predetermined maximum reduction in efficiency of the phosphor at increasing excitation density, a maximum dopant concentration of the phosphor layer is selected.

Abstract: A structure according to embodiments of the invention includes a light emitting device for emitting light having a first peak wavelength. A wavelength converting layer is disposed in a path of light emitted by the light emitting device. The wavelength converting layer absorbs light emitted by the light emitting device and emits light having a second peak wavelength. The wavelength converting layer includes a mixture of a wavelength converting material, a transparent material, and an adhesive material, wherein the adhesive material is no more than 15% of the weight of the wavelength converting layer.

Abstract: An LED module includes a substrate having a high thermal conductivity and at least one LED die mounted on the substrate. A wavelength conversion material, such as phosphor or quantum dots in a binder, has a very low thermal conductivity and is formed to have a relatively high volume and low concentration over the LED die so that the phosphor or quantum dots conduct little heat from the LED die. A transparent top plate, having a high thermal conductivity, is positioned over the wavelength conversion material, and a hermetic seal is formed between the top plate and the substrate surrounding the wavelength conversion material. The LED die is located in a cavity in either the substrate or the top plate. In this way, the temperature of the wavelength conversion material is kept well below the temperature of the LED die. The sealing is done in a wafer level process.