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We present a simple and general method of aspheric figure metrology using a CGH null mounted in the test beam of a conventional Fizeau or Twyinan-Green interferometer. A "standard" reflective CGH is used to establish optical alignment with respect to the interferometer's spherical test beam. This alignment is then mechanically transferred to a custom CGH null. The accuracy of the alignment transfer is readily verified. The test method has been modeled by raytracing and verified experimentally by testing a perforated 8-inch F/1.5 on-axis paraboloid and a 50 mm F/2 off-axis paraboloid from their centers of curvature.

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As part of the design and development effort for the “Hybrid Lighting System,” Oak Ridge National Laboratory (ORNL) scientists have evaluated two potential candidate-tracking systems for the solar collector. The first system, the WattSun Solar Tracker, built by Array Technologies, utilizes a patented, closed loop, optical sun sensor to sense the sun’s position and track it. The second tracking system, SolarTrak Controller, built by Enhancement Electronics, Inc., is a micro controller-based tracking system. The SolarTrak micro controller-based Tracker’s sun position is determined by computing the celestial bearing of the sun with respect to the earth using the local time, date, latitude, longitude and time zone rather than sensing the relative bearing of the sun with optical receptors. This system connects directly to the mechanical system hardware supplied by Array Technologies. Both the WattSun Solar Tracker and the SolarTrak Controller were mounted on the prototype “Hybrid Lighting” mechanical system (array) hardware. A simple switch allowed independent testing of each system. Upon completion of the evaluation of the two systems we found the WattSun Solar Tracker controller to be unacceptable for use with our prototype hybrid lighting system. The SolarTrak Controller has performed well to date and provides suitable tracking accuracy for use with our prototype “Hybrid Lighting System”. After a six-month evaluation period at ORNL, the first prototype “Hybrid Lighting System” was installed at Ohio University as part of an “Enhanced Practical Photosynthetic CO2 Mitigation.” This document will highlight the results of the tracker investigation and outline the remaining issues to be addressed, to provide a suitable tracking system for our “Hybrid Lighting” collector.

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We report on the performance of a new hybrid luminaire designed to blend light from a fiber optic solar source with electric fluorescent lamps. The luminaire design studied involves a commercially-available fluorescent luminaire that had been modified to include optical elements for efficiently dispersing a fiber optic solar light source. Quantitative measurements of the hybrid luminaire’s optical efficiency and spatial intensity distribution/deviations are discussed. The effects of static differences and dynamic fluctuations in spatial intensity distribution are qualitatively discussed and potential design improvements examined.

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