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Proceedings Paper

Optical transmittance of high-efficiency cavity with photon recycling
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Paper Abstract

A planar-exit lighting surface is not only used in the luminaires but also useful in the display backlights and other illumination systems. Most planar-exit lighting surfaces are made by edge-lit with line light source or 1-D LED array. If it is not edge-lit type, the light source can be two-dimensional, but a cavity is required. In this paper, a high-efficiency cavity providing extremely high energy transmittance with photon recycling is reported and demonstrated. The cavity contains a diffuser and the high reflectivity surfaces. The optical efficiency of the cavity is calculated by a formula with considering photon recycling. Furthermore, various kinds of diffusers are applied to change the optical transmittance as well as the light pattern. When the reflectivity of the inner wall of the lighting cavity is about 96 %, the optical efficiency of the cavity is higher than 90 % with several diffusers. The experimental measurement as well as the calculation is demonstrated in the paper.

Paper Details

Date Published: 21 September 2011
PDF: 5 pages
Proc. SPIE 8128, Current Developments in Lens Design and Optical Engineering XII; and Advances in Thin Film Coatings VII, 812805 (21 September 2011); doi: 10.1117/12.893230
Show Author Affiliations
Che-Chu Lin, National Central Univ. (Taiwan)
Xuan-Hao Lee, National Central Univ. (Taiwan)
Wei-Ting Chien, National Central Univ. (Taiwan)
Hen-Xiang Chen, National Central Univ. (Taiwan)
Ching-Cherng Sun, National Central Univ. (Taiwan)


Published in SPIE Proceedings Vol. 8128:
Current Developments in Lens Design and Optical Engineering XII; and Advances in Thin Film Coatings VII
R. Barry Johnson; Virendra N. Mahajan; Simon Thibault, Editor(s)

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