Abstract: A variety of illumination devices are disclosed that are configured to manipulate light provided by one or more light-emitting elements (LEEs). In general, embodiments of the illumination devices feature one or more optical couplers that redirect illumination from the LEEs to a reflector which then directs the light into a range of angles. In some embodiments, the illumination device includes a second reflector that reflects at least some of the light from the first reflector. In certain embodiments, the illumination device includes a light guide that guides light from the collector to the first reflector. The components of the illumination device can be configured to provide illumination devices that can provide a variety of intensity distributions. Such illumination devices can be configured to provide light for particular lighting applications, including office lighting, task lighting, cabinet lighting, garage lighting, wall wash, stack lighting, and downlighting.

Abstract: The thickness of an organic material on a substrate, such as an oil film on a metal sheet (12), is monitored by illuminating the film with ultraviolet radiation (14) and measuring the fluorescent light intensity (44, 48) from the organic material. The reflectivity of the substrate is also monitored, and used in calculating the thickness. The technique is also applicable where the substrate is moving.