We establish a fundamental bound on the field of view over which strictly uniform far-field irradiance can be achieved in symmetric 2D (trough-like) and 3D (cone-like) illumination systems. Earlier results derived for particular 2D devices are shown to be special cases of the general formula. For a rotationally-symmetric 3D luminaire with a lambertian disc light source and a prescribed uniform cone region half-angle (theta) c, no more than tan2((theta) c) can be projected within a uniform core region. Hence the efficiency with which such illuminators can produce uniform flux is severely limited for many problems of practical interest. Being guided by the Tailored Edge-ray Device formalism for the design of 2D luminaires, we develop a 3D reflector that produces extremely uniform far-field illuminance.
|Number of pages||7|
|Journal||Proceedings of SPIE - The International Society for Optical Engineering|
|State||Published - 1 Dec 1997|
|Event||Nonimaging Optics: Maximum Efficiency Light Transfer IV - San Diego, CA, United States|
Duration: 27 Jul 1997 → 27 Jul 1997
- Optical design
- Uniform irradiance