Abstract: A steerable illumination fixtures include an emitting source and a refractive optical system that steers an emitted beam by relative translation of the emitting source against the optical system. The light emitting source may be placed along an optical axis of one or more lenses to produce an output beam along that axis, or translated in-plane (orthogonal to the optical axis) relative to the lenses to produce a steered beam. The optical system may include refractive lenses and in some embodiments mixing channels and/or one or more baffles with apertures. The design is typically optimized to produce a round, uniform beam that retains approximately the same power level and beam width as it is steered. It is beneficial, but not required, that a second lens have a diameter equal to or larger than a first lens. The lenses may be configured so that the effective focal plane of the two lenses together is located approximately at the plane of the light emitting source.

Abstract: An array of LEDs is supported by a support mechanism that both supports conductors leading to the LEDs and sinks heat from the LEDs. The support mechanism may be a transparent heat-conducting sheet or an array of cantilevered arms at different angles that support the LEDs and sink heat. This reduces the blockage of light. The LEDs are positioned generally in the focal plane of an array of concave mirrors that collimate the light. The LEDs and array of mirrors are translatable with respect to one another to steer the aggregate light beam to customize the emission. The LEDs may be variably oriented with respect to the associated mirror apertures so as to create different light beams emitted from different ones of the mirrors.

Abstract: An array of LEDs is supported by a support mechanism that both supports conductors leading to the LEDs and sinks heat from the LEDs. The support mechanism may be a transparent heat-conducting sheet or an array of cantilevered arms at different angles that support the LEDs and sink heat. This reduces the blockage of light. The LEDs are positioned generally in the focal plane of an array of concave mirrors that collimate the light. The LEDs and array of mirrors are translatable with respect to one another to steer the aggregate light beam to customize the emission. In another embodiment, multiple LEDs are positioned over each mirror in the mirror array, and the combination of LEDs illuminated over each mirror is used to steer the aggregate light beam from the luminaire.

Abstract: The system captures and concentrates sunlight for transmission to interior spaces or to a PV system. A solar collector uses arrayed refractive lenses, opposing concave focusing mirrors, and a movable coupling sheet forming part of a lightguide. The lenses and mirrors have an asymmetric shape, such as having aspect ratios of 3:4 or 1:2, so as to have an asymmetric aperture to better receive light at the different ranges of angles of the sun's rays over the course of a year. The long axis of the apertures is generally oriented in an East-West. The movable sheet contains small angled mirrors, and the sheet is translated to position the angled mirrors at the focal points of the sunlight for maximum deflection of the sunlight to an output of the collection system. A position sensor provides feedback regarding the position of the angled mirrors relative to the focal points.

Abstract: The system captures and concentrates sunlight for transmission to interior spaces or to a PV system. A solar collector uses arrayed refractive lenses and opposing concave focusing mirrors and a movable coupling sheet forming part of a lightguide. The transparent sheet contains small angled mirrors, where each angled mirror corresponds to a particular set of the lenses/focusing mirrors and is in the focal plane. The lightguide also includes a fluid surrounding the transparent sheet, and lower index cladding layers sandwich the fluid. The sheet is translated within the fluid by an actuator to position the angled mirrors at the focal points of the sunlight for maximum deflection of the sunlight to an edge of the lightguide for extraction to a light transmission system or to a PV system. A position sensor on the sheet provides feedback regarding the position of the angled mirrors relative to the focal points.

Abstract: An array of LEDs is supported by a support mechanism that both supports conductors leading to the LEDs and sinks heat from the LEDs. The support mechanism may be a transparent heat-conducting sheet or an array of cantilevered arms at different angles that support the LEDs and sink heat. This reduces the blockage of light. The LEDs are positioned generally in the focal plane of an array of concave mirrors that collimate the light. The LEDs and array of mirrors are translatable with respect to one another to steer the aggregate light beam to customize the emission. In another embodiment, multiple LEDs are positioned over each mirror in the mirror array, and the combination of LEDs illuminated over each mirror is used to steer the aggregate light beam from the luminaire.

Abstract: The system captures and concentrates sunlight for transmission to interior spaces or to a PV system. A solar collector uses arrayed refractive lenses, opposing concave focusing mirrors, and a movable coupling sheet forming part of a lightguide. The lenses and mirrors have an asymmetric shape, such as having aspect ratios of 3:4 or 1:2, so as to have an asymmetric aperture to better receive light at the different ranges of angles of the sun's rays over the course of a year. The long axis of the apertures is generally oriented in an East-West. The movable sheet contains small angled mirrors, and the sheet is translated to position the angled mirrors at the focal points of the sunlight for maximum deflection of the sunlight to an output of the collection system. A position sensor provides feedback regarding the position of the angled mirrors relative to the focal points.

Abstract: A luminaire for providing configurable static lighting or dynamically-adjustable lighting. The luminaire uses an array of focusing elements that act on light provided via a corresponding array of sources or via an edge-lit lightguide. Designs are provided for adjusting the number of distinct beams produced by the luminaire, as well as the angular width, angular profile, and pointing angle of the beams. Designs are also provided for systems utilizing the adjustable luminaires in various applications.

Abstract: The system captures and concentrates sunlight for transmission to interior spaces or to a PV system. A solar collector uses arrayed refractive lenses and opposing concave focusing mirrors and a movable coupling sheet forming part of a lightguide. The transparent sheet contains small angled mirrors, where each angled mirror corresponds to a particular set of the lenses/focusing mirrors and is in the focal plane. The lightguide also includes a fluid surrounding the transparent sheet, and lower index cladding layers sandwich the fluid. The sheet is translated within the fluid by an actuator to position the angled mirrors at the focal points of the sunlight for maximum deflection of the sunlight to an edge of the lightguide for extraction to a light transmission system or to a PV system. A position sensor on the sheet provides feedback regarding the position of the angled mirrors relative to the focal points.

Abstract: An automatic optical coupling device that uses liquid to couple focused light into a light-guide is described. The liquid moves within a chamber or layer via the thermocapillary effect in order to automatically track and couple a moving spot of focused light. Also provided is the application of these coupling devices in an array feeding into a common light-guide, optical designs to improve the performance of these arrays, and the application of such arrays to light collection.

Abstract: An automatic optical coupling device that uses liquid to couple focused light into a light-guide is described. The liquid moves within a chamber or layer via the thermocapillary effect in order to automatically track and couple a moving spot of focused light. Also provided is the application of these coupling devices in an array feeding into a common light-guide, optical designs to improve the performance of these arrays, and the application of such arrays to light collection.

Abstract: A photonic device designed with an intermittent absorption profile along a waveguide. The absorption profile is divided into low-absorption and high-absorption segments that are distributed axially in order to decrease the maximum local temperature in the device. The distribution of low-absorption segments can be controlled through techniques such as proton implantation or selective-area quantum well intermixing. The lengths of low-absorption and high-absorption segments can be adjusted to optimize heat dissipation along the device length.

Abstract: A photonic device designed with an intermittent absorption profile along a waveguide. The absorption profile is divided into low-absorption and high-absorption segments that are distributed axially in order to decrease the maximum local temperature in the device. The distribution of low-absorption segments can be controlled through techniques such as proton implantation or selective-area quantum well intermixing. The lengths of low-absorption and high-absorption segments can be adjusted to optimize heat dissipation along the device length.

Abstract: A solar blind p-i-n photodiode where the active i-region has a bandgap larger than the bandgap of one or both of the n-type and p-type regions. The preferred embodiment photodiode is GaN based and Al is added to the regions to obtain the desired bandgap profiles. Al is added to the i-region to obtain a bandgap large enough to be responsive to light in the solar blind spectrum. By having a smaller bandgap p-type and n-type region, the problems associated with growing highly doped AlGaN are avoided. In most embodiments the light incident on the photodiode illuminates the p-type region first. The p-type region is grown thin compared to conventional photodiodes which allows the majority of light incident to pass through the p-type region to the i-region. Light with sufficient energy will be detected in the i-region. The inventive photodiode can also be used in the fabrication of backside illuminated solar blind photodiodes that are useful for photodiode arrays.

Abstract: Growth of doped gallium nitride, especially p-type gallium nitride, without using post-growth processing is achieved by eliminating hydrogen containing molecules from the growth process before cooling down the substrate. Rapid cooling of the substrate with nitrogen gas prevents the reaction of p-type dopant atoms with hydrogen, and the use of the nitrogen gas also keeps the nitrogen intact within the crystalline structure.