Abstract: One embodiment of a method of calculating an optical surface comprises calculating a meridional optical line of the surface. A ray is selected that passes a known point defining an end of a part of the optical line already calculated. The optical line is extrapolated from the known point to meet the ray using a polynomial with at least one degree of freedom. The polynomial is adjusted as necessary so that the selected ray is deflected at the extrapolated optical line to a desired target point. The polynomial is added to the optical line up to the point where the selected ray is deflected. The point where the selected ray is deflected is used as the known point in a repetition of those steps.

Abstract: One optical system comprises a first optical surface, a faceted second optical surface, and a faceted third optical surface. The optical system is operative to convert a first bundle of rays that is continuous in phase space outside the first optical surface into a second bundle of rays that is continuous in phase space outside the third optical surface. Between the second and third optical surfaces the rays making up the first and second bundles form discrete sub-bundles each passing from a facet of the second optical surface to a facet of the third optical surface. The sub-bundles do not form a continuous bundle in a phase space that has dimensions representing the position and angle at which rays cross a surface transverse to the bundle of rays.

Abstract: One example of a solar voltaic concentrator has a primary Fresnel lens with multiple panels, each of which forms a Köhler integrator with a respective panel of a lenticular secondary lens. The resulting plurality of integrators all concentrate sunlight onto a common photovoltaic cell. Luminaires using a similar geometry are also described.

Abstract: An optoelectrical device, which may be a luminaire or a photovoltaic concentrator, has a transparent cover plate. A target with an optoelectrical transducer that produces waste heat in operation is mounted at an inside face of the transparent cover plate. A primary mirror reflects light between being concentrated on the target and passing generally collimated through the cover plate. A heat spreader is in thermal contact with the target. The heat spreader has heat conductors that thermally connect the target with the inside surface of the cover plate. The heat conductors may be arms extending radially outwards, and may be straight, zigzag, or branching. An array of targets may be mounted on a common cover plate, and their heat spreaders may be continuous from target to target.

Abstract: An optoelectronic cooling system is equally applicable to an LED collimator or a photovoltaic solar concentrator. A transparent fluid conveys heat from the optoelectronic chip to a hollow cover over the system aperture. The cooling system can keep a solar concentrator chip at the same temperature as found for a one-sun flat-plate solar cell. Natural convection or forced circulation can operate to convey heat from the chip to the cover.

Abstract: The diffuse reflectivity of an LED source is utilized to recycle some of its emission, thereby enabling a luminaire to escape the étendue limit. Retroreflectors intercept the rays destined for the outer part of the luminaire aperture, which can then be truncated. The resulting smaller aperture has the same beam-width as the full original, albeit with lesser flux due to recycling losses. A reduction to half the original area is possible.

Abstract: One example of a solar photovoltaic concentrator has a primary mirror with multiple free-form panels, each of which forms a Köhler integrator with a respective panel of a lenticular secondary lens. The Köhler integrators are folded by a common intermediate mirror. The resulting plurality of integrators all concentrate sunlight onto a common photovoltaic cell. Luminaires using a similar geometry are also described.

Abstract: Some photovoltaic cells have a front face accepting incoming incident light and opaque gridlines overlying part of the front face, electrically bonded to the face, with upper reflective facets oblique to the plane of the front face and producing outgoing reflected light. An optical interface parallel to and in front of the front face transmits incoming light to the front face and to the gridlines and reflects back towards the front face by total internal reflection at least some of the outgoing reflected light. Some photovoltaic devices have a triple junction photovoltaic cell, a single junction photovoltaic cell, and a reflective surface arranged to distribute incoming light between the cells. The surface may be a frequency-selective mirror that apportions light so when the cells are in series the power produced, and preferably the photocurrent, is greater than if all the light fell on the triple junction cell alone.

Abstract: The present embodiments provide systems, backlights, films, apparatuses and methods of generating back lighting. Some embodiments provide backlights that include a cavity with at least one interior light source and diffusely reflecting wall of high reflectivity, a top surface with multiple intermittently spaced holes allowing exit of light generated by the light sources, and external collimators extending from each of the holes such that the external collimators spatially expand and angularly narrow the light exiting the holes.

Abstract: The present embodiments provide methods and systems for use in providing enhanced illumination. Some embodiments include at least two light sources and one or more smoothly rotating wheels, where the one or more wheels comprises at least one mirror sector, the circumferential portion of the mirror sector is the inverse of the number of said sources, a first source of the sources is so disposed that the mirror sector reflects light from the first source into a common output path, where the first source pulsing such that a duty cycle of the first source corresponds to a time the mirror sector reflects light from the first source into the common output path.

Abstract: A tubular luminaire efficiently utilizes the light of a line of high-brightness unlensed LEDs to reproduce the homogeneous appearance of a neon tube. The transparent tube has an annular cross-section suitable for cost-effective manufacturing by extrusion. The LEDs are mounted in a line on a circuit board that can be positioned either inside or outside the tube. Their light shines into a cylindrical groove, thereby entering within the material of the tube. Above the groove, the wall of the tube has a spiral shape that reflects the light laterally so that it stays within the annular tube for a considerable path length. Volume scattering by a low density of scattering inclusions causes the light to escape as a homogenous glow. Alternatively, mild surface scattering from the inside surface can be used.

Abstract: An optical device for coupling the luminous output of a light-emitting diode (LED) to a predominantly spherical pattern comprises a transfer section that receives the LED's light within it and an ejector positioned adjacent the transfer section to receive light from the transfer section and spread the light generally spherically. A base of the transfer section is optically aligned and/or coupled to the LED so that the LED's light enters the transfer section. The transfer section can comprises a compound elliptic concentrator operating via total internal reflection. The ejector section can have a variety of shapes, and can have diffusive features on its surface as well. The transfer section can in some implementations be polygonal, V-grooved, faceted and other configurations.

Abstract: A waveguide version of a Kohler integrator is disclosed, utilizing geodesic lenses with a surface that can be mapped to a gradient-index Luneburg lens or to a nonfull-aperture Luneburg lens in such a way that the light paths in the gradient index lenses map into the geodesics of the surface, with the outer region of the gradient index lenses mapped into a flat surface. Arrays of these can be applied to lines of LEDs, as in CHMSLs, to mix light in intensity and in illumination as well as to avoid the deleterious effects of binning and burnout, or in multicolor arrays, to ensure complete chromatic mixing.

Abstract: High-concentration photovoltaic concentrators can utilize much more expensive high-efficiency cells because they need so much less of them, but much of the solar resource is left ungathered thereby. The main cell is at the focal spot of the concentrator. Low-cost secondary solar cells are now added to the concentrator, surrounding the main cell. Diffuse skylight and misdirected normal rays irradiate these secondary cells, adding to output. Also, the power plant can have output on cloudy days, unlike conventional concentrators. As cell costs fall relative to other costs, this system becomes economically superior to both flat-plate and concentrator systems.

Abstract: An embodiment of an optical manifold has first and second collimators, each arranged to receive light from a source and transmit the light to an exit port of the collimator, and a separator arranged to emit some of the light from the exit ports of the first and second collimators and to recycle some of the light into the collimators. Another embodiment has at least three collimators of substantially equal length and having central axes, respective light sources at entry ports of the collimators, the collimators being arranged with their central axes parallel and with their light sources in a common plane and reflectors positioned to direct light from exit ports of the collimators to a selectively reflective component that guides all the light into a common exit beam.

Abstract: One example of a solar voltaic concentrator has a primary Fresnel lens with multiple panels, each of which forms a Köhler integrator with a respective panel of a lenticular secondary lens. The resulting plurality of integrators all concentrate sunlight onto a common photovoltaic cell. Luminaires using a similar geometry are also described.

Abstract: Optical systems are described that have at least one source of a beam of blue light with divergence under 15°. A phosphor emits yellow light when excited by the blue light. A collimator is disposed with the phosphor and forms a yellow beam with divergence under 15°. A dichroic filter is positioned to transmit the beam of blue light to the phosphor and to reflect the beam of yellow light to an exit aperture. In different embodiments, the beams of blue and yellow light are incident upon said filter with central angles of 15°, 22°, and 45°. The filter may reflect all of one polarization and part of the other polarization, and a polarization rotating retroreflector may then be provided to return the unreflected light to the filter.

Abstract: Some embodiments provide a luminance-enhanced light source. These embodiments include a thin-film LED mounted on a substrate and with a defined upper surface approximately hemispherically emitting light, with the upper surface being diffusely transmissive, a lower first layer of identically defined linear prismatic film separated from the upper surface by a non-evanescent air gap so as to cover the upper surface, a upper second layer of linear prismatic film, identical to but oriented orthogonally to the first layer, and a circumferential vertical reflective wall bordering on both of the first and second layers and extending in height from the substrate to the top of the second layer.

Abstract: One embodiment of a method of calculating an optical surface comprises calculating a meridional optical line of the surface. A ray is selected that passes a known point defining an end of a part of the optical line already calculated. The optical line is extrapolated from the known point to meet the ray using a polynomial with at least one degree of freedom. The polynomial is adjusted as necessary so that the selected ray is deflected at the extrapolated optical line to a desired target point. The polynomial is added to the optical line up to the point where the selected ray is deflected. The point where the selected ray is deflected is used as the known point in a repetition of those steps.

Abstract: The present embodiments provide methods and systems for use in providing enhanced illumination. Some embodiments include at least two light sources and one or more smoothly rotating wheels, where the one or more wheels comprises at least one mirror sector, the circumferential portion of the mirror sector is the inverse of the number of said sources, a first source of the sources is so disposed that the mirror sector reflects light from the first source into a common output path, where the first source pulsing such that a duty cycle of the first source corresponds to a time the mirror sector reflects light from the first source into the common output path.