Abstract: Ultraviolet irradiation of fluids for the purposes of disinfection, sterilization and modification of a target organic compound found within the fluids. The target compound in the fluids can have an absorption spectra with an ultraviolet wavelength ranging from 230 nm to 360 nm. The absorption spectra includes a first and second set of wavelengths corresponding to absorption peaks and absorption valleys in the absorption spectra, respectively. A-set of ultraviolet radiation sources irradiate the fluids. The set of ultraviolet radiation sources operate at a set of peak wavelengths ranging from 230 nm to 360 nm with a peak full width at half maximum that is less than 20 nm. The set of peak wavelengths are proximate to at least one wavelength in the second set of wavelengths corresponding to the absorption valleys in the absorption spectra with a variation of a full width half maximum of the absorption valley.

Abstract: Approaches for evaluating fluid flow based on fluorescent sensing is disclosed. In one approach, a nanoparticle injector is configured to inject nanoparticles into fluid flowing through a conduit. A detector is configured to determine a presence of the nanoparticles in the flow of the fluid. The detector can include a radiation source configured to irradiate the fluid with a target radiation and a fluorescent meter configured to measure an amount of fluorescence emitted from the fluid irradiated with the radiation. A control unit is configured to determine the flow of the fluid in the conduit as a function of the measured amount of fluorescence.

Abstract: A semiconductor heterostructure for an optoelectronic device with improved light emission is disclosed. The heterostructure can include a first semiconductor layer having a first index of refraction n1. A second semiconductor layer can be located over the first semiconductor layer. The second semiconductor layer can include a laminate of semiconductor sublayers having an effective index of refraction n2. A third semiconductor layer having a third index of refraction n3 can be located over the second semiconductor layer. The first index of refraction n1 is greater than the second index of refraction n2, which is greater than the third index of refraction n3.

Abstract: A heterostructure, such as a group III nitride heterostructure, for use in an optoelectronic device is described. The heterostructure can include a sacrificial layer, which is located on a substrate structure. The sacrificial layer can be at least partially decomposed using a laser. The substrate structure can be completely removed from the heterostructure or remain attached thereto. One or more additional solutions for detaching the substrate structure from the heterostructure can be utilized. The heterostructure can undergo additional processing to form the optoelectronic device.

Abstract: A solution for illuminating an area and/or treating a substance with light, such as ultraviolet radiation, is described. The solution can use one or more solid state ultraviolet sources in conjunction with one or more ultraviolet lamps to illuminate a treatment region with ultraviolet radiation. A control component can individually operate the solid state ultraviolet source(s) and the ultraviolet lamp(s) to illuminate the treatment region with ultraviolet radiation having a predetermined minimum ultraviolet intensity.

Abstract: An approach for the treatment of surfaces in public places with ultraviolet light is disclosed. In one embodiment, a disinfection illuminator having ultraviolet radiation sources can irradiate a number of contact surfaces. A control unit can control the ultraviolet irradiation of the contact surfaces. The disinfection illuminator is suitable for a wide variety of devices that are used by the general public. Gas station pumps, door knobs, key pads, and bathrooms are illustrative of examples of some devices and places having commonly-used surfaces that can be treated by the disinfection illuminator.

Abstract: An approach for controlling ultraviolet intensity over a surface of a light sensitive object is described. Aspects involve using ultraviolet radiation with a wavelength range that includes ultraviolet-A and ultraviolet-B radiation to irradiate the surface. Light sensors measure light intensity at the surface, wherein each sensor measures light intensity in a wavelength range that corresponds to a wavelength range emitted from at least one of the sources. A controller controls the light intensity over the surface by adjusting the power of the sources as a function of the light intensity measurements. The controller uses the light intensity measurements to determine whether each source is illuminating the surface with an intensity that is within an acceptable variation with a predetermined intensity value targeted for the surface. The controller adjusts the power of the sources as a function of the variation to ensure an optimal distribution of light intensity over the surface.

Abstract: A semiconductor heterostructure for an optoelectronic device includes a base semiconductor layer having one or more semiconductor heterostructure mesas located thereon. One or more of the mesas can include a set of active regions having multiple main peaks of radiative recombination at differing wavelengths. For example, a mesa can include two or more active regions, each of which has a different wavelength for the corresponding main peak of radiative recombination. The active regions can be configured to be operated simultaneously or can be capable of independent operation. A system can include one or more optoelectronic devices, each of which can be operated as an emitter or a detector.

Abstract: A solution for illuminating plants is provided. An illustrative system can include: a set of visible light sources configured to emit visible radiation directed at the plant; a set of ultraviolet radiation sources configured to emit ultraviolet radiation directed at the plant; and a set of sensors, wherein at least one sensor is configured to detect a fluorescence emitted from the plant due to the ultraviolet radiation and a fluorescence emitted from the plant due to the visible radiation.

Abstract: A heterostructure, such as a group III nitride heterostructure, for use in an optoelectronic device is described. The heterostructure can include a sacrificial layer, which is located on a substrate structure. The sacrificial layer can be at least partially decomposed using a laser. The substrate structure can be completely removed from the heterostructure or remain attached thereto. One or more additional solutions for detaching the substrate structure from the heterostructure can be utilized. The heterostructure can undergo additional processing to form the optoelectronic device.

Abstract: An approach for controlling light exposure of a light sensitive object is described. Aspects of this approach involve using a first set of radiation sources to irradiate the object with visible radiation and infrared radiation. A second set of radiation sources spot irradiate the object in a set of locations with a target ultraviolet radiation having a range of wavelengths. Radiation sensors detect radiation reflected from the object and environment condition sensors detect conditions of the environment in which the object is located during irradiation. A controller controls irradiation of the light sensitive object by the first and second set of radiation sources according to predetermined optimal irradiation settings specified for various environmental conditions. In addition, the controller adjusts irradiation settings of the first and second set of radiation sources as a function of measurements obtained by the various sensors.

Abstract: A semiconductor heterostructure for an optoelectronic device is disclosed. The semiconductor heterostructure includes at least one stress control layer within a plurality of semiconductor layers used in the optoelectronic device. Each stress control layer includes stress control regions separated from adjacent stress control regions by a predetermined spacing. The stress control layer induces one of a tensile stress and a compressive stress in an adjacent semiconductor layer.

Abstract: A device comprising a semiconductor layer including a plurality of compositional inhomogeneous regions is provided. The difference between an average band gap for the plurality of compositional inhomogeneous regions and an average band gap for a remaining portion of the semiconductor layer can be at least thermal energy. Additionally, a characteristic size of the plurality of compositional inhomogeneous regions can be smaller than an inverse of a dislocation density for the semiconductor layer.

Abstract: An approach for curing ultraviolet sensitive polymer materials (e.g., polymer inks, coatings, and adhesives) using ultraviolet radiation is disclosed. The ultraviolet sensitive polymer materials curing can utilize ultraviolet light at different wavelength emissions arranged in a random, mixed or sequential arrangement. In one embodiment, an ultraviolet light C (UV-C) radiation emitter having a set of UV-C sources that emit UV-C radiation at a predetermined UV-C duration and intensity operate in conjunction with an ultraviolet light B (UV-B) radiation emitter having a set of UV-B sources configured to emit UV-B radiation at a predetermined UV-B duration and intensity and/or an ultraviolet light A (UV-A) radiation emitter having a set of UV-A sources configured to emit UV-A radiation at a predetermined UV-A duration and intensity, to cure the ultraviolet sensitive polymer materials.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The heterostructure can include a p-type interlayer located between the electron blocking layer and the p-type contact layer. In an embodiment, the electron blocking layer can have a region of graded transition. The p-type interlayer can also include a region of graded transition.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The electron blocking layer is located between the active region and the p-type contact layer. In an embodiment, the electron blocking layer can include a plurality of sublayers that vary in composition.

Abstract: An optoelectronic device configured for improved light extraction through a region of the device other than the substrate is described. A group III nitride semiconductor layer of a first polarity is located on the substrate and an active region can be located on the group III nitride semiconductor layer. A group III nitride semiconductor layer of a second polarity, different from the first polarity, can located adjacent to the active region. A first contact can directly contact the group III nitride semiconductor layer of the first polarity and a second contact can directly contact the group III nitride semiconductor layer of the second polarity. Each of the first and second contacts can include a plurality of openings extending entirely there through and the first and second contacts can form a photonic crystal structure. Some or all of the group III nitride semiconductor layers can be located in nanostructures.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The p-type contact layer and electron blocking layer can be doped with a p-type dopant. The dopant concentration for the electron blocking layer can be at most ten percent the dopant concentration of the p-type contact layer. A method of designing such a heterostructure is also described.

Abstract: A solution for cleaning and/or sterilizing one or more surfaces in a bathroom is provided. The sterilization can be performed using ultraviolet sources, which can emit ultraviolet radiation directed onto the surface(s). The cleaning can be performed using a fluid, such as water, that is flowed over the surface(s). The surface(s) can include at least a seat of a toilet and/or other surfaces associated with the toilet.

Abstract: A growth layer having a growth surface with protruding domains is described. The protruding domains can be separated by a substantially flat growth surface located between the protruding domains. A protruding domain can include an internal region that can be filled with a gas and/or can be partially or completely filled with one or more materials that differ from the material of the growth layer, which forms an outer surface of each of the protruding domains.