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Proceedings Paper

Lambertian surfaces to tailor the distribution of light in a nonimaging optical system
Author(s): David P. Ramer; Jack C. Rains Jr.
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Paper Abstract

In this paper we will introduce a new light distribution technique we term `Constructive Occlusion'. Using the geometry of Constructive Occlusion, diffuse surfaces can be used to tailor the distribution of a light source, eliminating the need for refractors or reflectors. The use of diffuse materials alone does not enable the tailoring of the distribution because lambertian materials distributed light as a cosine distribution. This cosine distribution is largely independent of the specific shape of the surface. Constructive Occlusion overcomes this limitation by the use of its patented geometry. Through application of the geometry, an integrating cavity is formed using a highly reflective diffuse material (>95% reflectivity). A mask is placed over the cavity, such that the light source and major portion of the cavity is occluded, enabling an interaction between the cavity and the mask. The arrangement and dimensions of the cavity opening, the mask, and the distance of the mask from the cavity, as well as several other geometric relationships, combine to control the light distribution of the optic. Contrary to expectations, we have been able to demonstrate our ability to shape the light distribution while maintaining high optical efficiencies, as high as 87% dependent upon the distribution. The specific techniques of constructive occlusion and example applications will be discussed in this paper.

Paper Details

Date Published: 6 October 1999
PDF: 12 pages
Proc. SPIE 3781, Nonimaging Optics: Maximum Efficiency Light Transfer V, (6 October 1999); doi: 10.1117/12.368252
Show Author Affiliations
David P. Ramer, Advanced Optical Technologies, L.L.C. (United States)
Jack C. Rains Jr., Science Applications International Corp. (United States)

Published in SPIE Proceedings Vol. 3781:
Nonimaging Optics: Maximum Efficiency Light Transfer V
Roland Winston, Editor(s)

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