標題: Irradiance formations in hollow straight light pipes with square and circular shapes
作者: Cheng, YK
Chern, JL
光電工程學系
Department of Photonics
公開日期: 1-二月-2006
摘要: We investigated, both analytically and numerically, the irradiance formation of an asymmetrically located Lambertian light source in hollow straight light pipes with square and circular shapes. The uniform irradiance distribution in a square light pipe and hot-spot localization in a circular light pipe were examined and determined semianalytically. Typical factors of influence, such as light-pipe length, width, and source size, were identified with extensive simulation. Mien the ratio of light-pipe length and width was less than 0.5, the deviation from uniformity could be more than 20%. But once the source size was large enough (approximately half of the incident port), such that the Lambertian characteristics of the source dominated the irradiance distribution, the uniformity deviation was reduced. Furthermore, a quantity of root-mean-square circular differences was defined in order to identify the shape deformation of the light pipe; it was found that the peak value of the hot spot decreased exponentially with the deformation scale. The influence of nonperfect reflectivity of the pipe wall on irradiance formation was also examined for a square light pipe; when the reflectivity is larger than 90%, the difference in uniformity is less than 10% and uniform irradiance remains, provided that the ratio of light-pipe length and width is larger than 1; even the source is located asymmetrically. (c) 2006 Optical Society of America.
URI: http://dx.doi.org/10.1364/JOSAA.23.000427
http://hdl.handle.net/11536/12672
ISSN: 1084-7529
DOI: 10.1364/JOSAA.23.000427
期刊: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
Volume: 23
Issue: 2
起始頁: 427
結束頁: 434
顯示於類別:期刊論文