Analysis of the far-field region of LEDs.
Versatility in the design of optical systems is one of the key features of light-emitting diodes (LEDs) that has attracted considerable attention. In the analysis of systems using LEDs, it is useful to know if the distance is far enough from the LED to allow the radiation pattern to be simulated by the point source approach. We propose three far-zone conditions for LED light modeling: the far-field distance, and for practical purposes the quasi far-field and minimum far-field distances. Different types of LEDs have different far-field ranges. We analyze these differences by modulating key parameters like geometrical structure of encapsulating lens, chip size, chip shape, chip position, and package errors. We find that far-field region considerably depends more on the shape of both lens and chip than all other parameters.
Sun
Ching-Cherng
CC
Department of Optics and Photonics, National Central University, Chung-Li 320, Taiwan. ccsun@dop.ncu.edu.tw
Chien
Wei-Ting
WT
Moreno
Ivan
I
Hsieh
Chih-Ching
CC
Lo
Yi-Chien
YC
D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D008962:Models, Theoretical; D055096:Optical Devices; D012542:Scattering, Radiation; D012666:Semiconductors